Pride, Philosophy, and the Corruption of Divine Truth: Tertullian’s Warning Then and Now

In every age, the greatest threat to truth comes cloaked in the glitter of human wisdom. The early Christian writer Tertullian saw this clearly. Living in a Roman world enamored with philosophy, he leveled a fierce polemic against pagan thought; arguing that Greek philosophies like Pythagoreanism, Platonism, and Stoicism were nothing but the pride of man masquerading as wisdom, fundamentally opposed to the humble truth of God. His critique is more than a historical curiosity. It sounds an alarm for today, when new movements of religious syncretism and “one-world” spirituality repeat the oldest deception: that divine truth can be discovered by our own speculation rather than received by revelation.

In this post, we’ll dive deep into Tertullian’s Apology (c. AD 200) and his other writings, to see how he dismantled the pretensions of pagan philosophy. We’ll explore how the Pythagoreans’ sacred tetractys – their numerological key to the cosmos – reflects a corrupted “tree of knowledge of good and evil,” an arrogant grasping after forbidden wisdom. We’ll hear Tertullian expose the contradictions of philosophers who confused God with nature or number, stole and distorted truths from Scripture, and even aligned with demons in their quest for knowledge. Finally, we’ll consider how the early church was infiltrated by this syncretistic pride, and how the same pattern is re-emerging today in modern interfaith trends. Tertullian’s voice from 1,800 years ago is startlingly relevant – and urgently needed – today.

Tertullian: The Apologist Who Asked “What has Athens to do with Jerusalem?”

Before turning to his polemic, let’s briefly meet Tertullian himself. Quintus Septimius Florens Tertullian (c. 155–225 AD) was a North African theologian from Carthage, a convert from Roman paganism who became one of the first great Christian Latin. Around AD 200, amid growing persecution of Christians, he penned his Apology as a defense of the faith to the Roman authorities. Tertullian was a passionate, no-nonsense polemicist with a lawyer’s training, famous for his scathing wit and absolute loyalty to biblical truth. He had little patience for blending Christian faith with Greco-Roman philosophy. In fact, he famously demanded: “What indeed has Athens to do with Jerusalem? What concord is there between the Academy and the Church? What between heretics and Christians?” In Tertullian’s metaphor, “Athens” represents human philosophy (the Academy of Plato, the Stoics’ porch, etc.), while “Jerusalem” represents the divine revelation of the Church. His answer to his own question was clear: Nothing. Our faith, he insisted, should rest on prophetic revelation in “simplicity of heart,” not on the sophistry of worldly wisdom.

Tertullian’s prescription was uncompromising: “Away with all attempts to produce a mottled Christianity of Stoic, Platonic, and dialectic composition!”. He did not want the gospel diluted with proud human ideas. “We want no curious disputation after possessing Christ Jesus,” he wrote, “with our faith, we desire no further belief. For this is our palmary faith, that there is nothing which we ought to believe besides.” In other words, Christ’s revelation is sufficient, and all the philosophical “coloring” only contaminates it.

This stance might sound anti-intellectual, but Tertullian’s target was not reason itself – it was prideful reason set above God. As we’ll see, he believed pagan philosophy wasn’t just wrong – it was an expression of spiritual rebellion, an echo of the serpent’s promise in Eden that “you will be like God, knowing good and evil” (Gen. 3:5). The philosophies of his day were, in his view, elaborate systems of human pride, idolatrous replacements for the true knowledge of God. And he marshaled both scripture and sharp logic to prove it.

The Pride at the Root of Pagan Philosophy

At the heart of Tertullian’s polemic is the charge that pagan philosophy is rooted in prideful self-will. The ancient philosophers, for all their learning, refused to submit humbly to God’s revealed truth. Instead, they trusted in their own reason as supreme. Tertullian saw this as the primal sin of humanity: the arrogant pursuit of knowledge on our own terms (like grasping the forbidden fruit of “the tree of knowledge” in Eden) rather than on God’s terms.

He points out that the Greek sages were not seekers of God in humility, but seekers of preeminence – founders of rival schools vying for fame. They each claimed to unlock the secrets of the universe, glorifying the human mind. This, Tertullian argues, led them into futility and contradiction. “Human wisdom,” he writes, “pretends to know the truth, [but] only corrupts it, and is itself divided into its own manifold heresies by the variety of its mutually repugnant sects.”. The proliferation of competing philosophical schools – Academy vs. Porch, Epicureans vs. Stoics, etc. – was evidence to him that prideful minds could not even agree on truth. Each philosopher, “too proud to believe” simple truth, instead concocted his own theory. In Tertullian’s withering judgment, their wisdom was ultimately folly – “made foolish” by God– because it sprang from arrogance and not from the “fear of the Lord” which is the beginning of wisdom (Prov. 9:10).

The Pythagorean “Tree of Knowledge”: Number Worship and Forbidden Wisdom

One vivid example of this prideful wisdom, which Tertullian highlights, is Pythagorean philosophy. The Pythagoreans exalted numbers as the key to the cosmos. They believed that the entire universe could be explained by mathematical relationships, epitomized in the tetractys – a triangular figure of ten points symbolizing the primal numbers (1 through 4 summed to 10) and the structure of reality.

The Pythagoreans treated “number” with divine honors: one ancient prayer even addresses “divine number, thou who generated gods and men… O holy Tetractys, thou that containest the root and source of the eternally flowing creation!”. In this mystical oath, the Pythagoreans literally equated number with the Creator, glorifying an abstract principle in place of the personal God. Historians note that Pythagoras’ followers considered the science of numbers to be “the origin of all things,” believing that to know numbers was equivalent to knowing God.

Tertullian regarded this as a prime example of idolatrous knowledge – the “tree of knowledge”. Just as Adam and Eve grasped at godlike knowledge by eating from the forbidden tree (Gen. 2:17, 3:6), the Pythagoreans grasped at divine status for human reason by declaring mathematical order itself to be god. They were, in effect, worshipping the creation (numbers, harmonies, cosmic order) instead of the Creator (cf. Rom. 1:25). Tertullian derided such ideas sharply: “Some, like Pythagoras, think [God] is composed of numbers”– reducing the Almighty to an equation! The tetractys was for them a source of secret wisdom to be exploited, rather than a creation to be received with thanks. In Tertullian’s eyes, this was nothing short of “impiety” – a proud refusal to acknowledge the true God, “too proud to believe” the simple truth of a Creator, and instead devising a convoluted cosmology of their own.

And where did this obsession lead? Not to enlightenment, but to folly and contradiction. For all their esoteric knowledge, the Pythagoreans and their ilk could not find the true God by counting and calculating. Their “tree of knowledge” bore poison fruit. As we shall see next, each philosopher’s proud system disagreed with the others, illustrating, in Tertullian’s view, that pride leads not to unity but to confusion – a Babel of clashing opinions.

The Serpent, the Stars, and the Counterfeit Tree of Knowledge

In the image of the tetractys encircled by the ouroboros serpent, we see the spiritual DNA of pagan philosophy laid bare. What looks like an elegant geometric figure is, in truth, a cosmogram of idolatry — a map of the heavens turned into a god, an altar to the powers of sun, moon, and planets.

The Ten Dots and the Seven Planetary Powers

The ten dots of the tetractys are no random decoration. For the Pythagoreans, they were the sacred decad, the perfection of number. But beneath the surface lies a darker meaning: these dots were mapped onto the celestial rulers of the cosmos.

• The Sun and Moon were counted as two great lights — the visible powers dominating day and night.

• The five wandering stars visible to the naked eye — Mercury, Venus, Mars, Jupiter, and Saturn — were honored as planetary gods.

• Together, these seven luminaries governed fate, time, and the destinies of men in pagan thought.

To reach the number ten, philosophers added the Earth itself as a body, and the sphere of fixed stars (the Zodiac) that enclosed all. Thus, the tetractys became a numerical temple to the “lords of heaven” — the astral powers worshiped in mystery cults, astrology, and philosophy.

This was nothing new. Since Babel, mankind has looked upward and bowed down to the host of heaven. Moses warned Israel against lifting eyes to the sun, moon, and stars, lest they be seduced into worship (Deut. 4:19). Yet here in the tetractys, the ancient philosophers proudly enshrined those very bodies as the highest principles of existence.

“And out of the bottomless pit came the beast… and it had ten horns, which are ten kings.” (cf. Revelation 17:7, 12; 11:7)

Encircling the triangle is the ouroboros, the serpent devouring its own tail. Pagans adored it as a symbol of eternity and self-contained life, but Scripture unmasks the truth: the serpent is the deceiver from the beginning.

By wrapping the tetractys, the serpent proclaims that the cosmos is eternal, cyclical, needing no Creator. Time is endless recurrence. Souls are trapped in reincarnation. History has no purpose, only repetition. This is the lie of Satan retold in geometry: “You shall not surely die” (Gen. 3:4). It denies both the Creator’s authority and the final judgment to come.

And so the philosophers worshiped the deceiver himself. In honoring the serpent of eternity, they exalted the very one who first enticed humanity to eat of the forbidden tree of knowledge. The tetractys is that tree redrawn — beautiful to the eye, promising wisdom, but poisoned at the root.

“Him that overcometh will I make a pillar in the temple of my God, and he shall go no more out: and I will write upon him the name of my God, and the name of the city of my God, which is new Jerusalem, which cometh down out of heaven from my God: and I will write upon him my new name.” Revelation 3:12

The Worship of the Heavens

In Pythagoreanism, Platonism, and later Roman religion, the celestial bodies were not mere creations but divinities to be adored. Saturn devoured his children. Jupiter hurled thunderbolts. Venus embodied desire. Mars bloodlust. The sun was hailed as invincible. The moon as a goddess of cycles and magic. To the pagan, the stars were not lamps hung by God, but masters to be appeased.

Thus the tetractys became a priestly diagram — a ladder of ascent, a code to align oneself with the planetary powers. This was the seed of astrology, the heart of mystery cults, the supposed wisdom of the philosophers. And it was nothing less than idolatry: worshiping the creature rather than the Creator.

The tragedy is that this idolatry does not remain an ancient relic. It is a living system of bondage. For ages, men in secret societies and occult brotherhoods have taken these very symbols — the serpent, the stars, the numbers — and used them to enslave mankind.

By exalting the heavens as rulers of fate, they bind humanity under the tyranny of astrology and destiny. By claiming special knowledge of the stars, they enthrone themselves as interpreters of fate, priests of hidden wisdom. They build their temples, trace their geometries, swear their oaths, all under the serpent’s coiled shadow. And in doing so, they worship not God, but their own pride.

This is the heart of secret society initiation: to promise deification through the serpent’s wisdom, to say, “You too shall be as gods.” But instead of divinization, it brings only slavery. The stars become chains, the serpent becomes master, and the pride of man becomes his own downfall.

Pagan Philosophers Confused God with Nature and Number

Tertullian spends a good portion of his Apology showing how the celebrated philosophers couldn’t even agree on the nature of God or the world. They theorized confidently – yet each theory contradicted the next, underscoring how unreliable human speculation is compared to divine revelation. He delights in cataloguing these contradictions to humble the pretensions of “worldly wisdom.” Consider a few of the mutually incompatible ideas various philosophers taught about God and the cosmos:

• Pythagoras – taught that the universe is ultimately made of numbers and is eternal and self-existent (no creation needed). In his view, “number” was the essence of reality, such that even God (if one speaks of God) was essentially the harmony of numerical relations.

• Plato – taught almost the opposite: that the cosmos was created by a supreme Craftsman (Demiurge) and had a beginning. Plato’s God was a transcendent Mind who formed the world (not numbers, and not eternal matter as others claimed). Yet Plato also placed the divine principle inside the world, like a soul within it, “as a pilot is in a ship.”

• Stoics – argued that God is nature, a corporeal fiery spirit pervading the world. The Stoics were essentially pantheists; some, Tertullian notes, pictured God “having a body” and even imagined Him “placed outside the world, whirling round this huge mass from without like a potter” shaping his clay. (Others Stoics identified God with the world-soul itself, contrary to Plato’s “pilot” analogy – again a disagreement.)

• Epicureans – flatly denied God’s governance of the world. While not denying that gods exist, Epicurus taught that the gods are completely indifferent, “idle and inactive… a nobody in human things,” living in eternal detachment. He also taught that all reality, including any gods, is composed of atoms – matter and void. Thus, for Epicureans, there was no providence, no divine plan – a view utterly at odds with Plato’s.

• Heraclitus – proposed that the fundamental principle of the universe (and thus of God) was fire. For him, everything was in flux and fire was the divine element driving cosmic change. This again conflicts with the Stoic idea of a rational ordering principle, and with Plato’s eternal Forms, etc.

Tertullian highlights these examples (and more) in Apology to make a biting point: How can we exalt these philosophers as lights of reason when their conclusions are so opaque and conflicted? 

“One thinks God is made of fire; another maintains He has no body; some say He’s inside the world, others outside; some call Him number, others atoms, others nothing at all!” (one can almost hear Tertullian’s sarcasm). Far from attaining a reliable knowledge of God, their pride left them groping in the dark, each grabbing a piece of creation and enthroning it as “god.” They “changed the glory of the incorruptible God into” elements and abstractions (cf. Rom. 1:22–23). In Tertullian’s words, “Finding a simple revelation of God, they proceeded to dispute about Him, not as He had revealed Himself to them, but turned aside to debate about His properties, His nature, His abode.”

They made easy things difficult and certain things uncertain by their incessant admixture of opinions.

The root of the problem, again, is human pride. The truth about God had been revealed – in the testimony of creation itself and, as Christians held, in the Scriptures and ultimately in Christ. But the philosophers were “too proud to believe” this truth as given. Instead, “the fastidiousness of man” led them to alter it, complicate it, and obscure it. Their “wisdom” was in fact an exercise in vanity: “professing to be wise, they became fools” (Rom. 1:22). Tertullian shows that by confusing God with nature or number – worshiping the creation (be it fire, stars, numbers, or the whole cosmos) – the philosophers ended up with a pile of mutually contradictory idolatries, not the truth.

This demonstration served Tertullian’s apologetic aim: to convince his Roman readers that Christian faith, grounded in God’s actual self-disclosure, was secure and coherent, whereas Greek philosophy was a maze of error and inconsistency. And worse, he argues, it was not innocent error—it was culpable, even demonic, error.

Stealing from Scripture: Philosophers as Plagiarists of Divine Truth

A striking accusation Tertullian makes is that the philosophers got whatever truths they did have from the revelations of God – only to distort and misapply them. Far from being independent discoverers of truth, he portrays them as plagiarists of the more ancient Hebrew Scriptures.

“There is nothing so old as the Truth,” he writes, noting that Moses and the prophets long predated the Greek sages. “What poet or sophist has not drunk at the fountain of the prophets?”. According to Tertullian, the philosophers dipped into the divine wellspring of truth but, lacking true faith, “watered their arid minds” only to twist the truths they found. “Ambitious of glory and eloquence alone, if they fell upon anything in the sacred Scriptures which displeased them, they perverted it to serve their purpose,” he says. They imitated bits of biblical doctrine while adulterating them to fit their own theories. And this pattern did not stop with the philosophers. In later centuries, the same spirit of human pride corrupted the once-given apostolic doctrine. What began as the simple faith of Christ and His apostles was weighed down with additions: Marian feasts with no command from Scripture, a papal throne claiming infallibility where Christ alone is Head, infant baptism where the apostles called for personal repentance and faith, man-made penances where the gospel proclaims repentance unto forgiveness, and a swelling list of rituals and sacraments where the New Testament enjoins only two. Each of these was not a gift of God, but a product of prideful invention ; men exalting their own wisdom above the Word once delivered to the saints.

For example, he suggests that Plato’s concept of a Creator and an immortal soul were borrowed from Moses’ account of creation. The Stoics’ idea of a fiery end for the world echoes the biblical idea of a final conflagration (2 Peter 3:7) – yet they turned it into a recurring cosmic cycle. The Pythagoreans with their emphasis on the soul’s immortality and the ethical duty of purification may have picked up echoes of biblical morality or Egyptian teachings ultimately rooted in Noahic traditions – yet they mixed them with reincarnation and numerology. Tertullian even notes that some Greek cities banned philosophy at times (Sparta, Thebes, etc.) because the philosophers were seen as promulgating foreign ideas – an allusion, perhaps, to the notion that their ideas were imported (from older cultures like the Egyptians and, by extension, the Hebrews).

However, the tragedy in Tertullian’s view is that “even what [the philosophers] found certain, they made uncertain by their admixtures” They might have started with a kernel of truth from God’s revelation, but pride and unbelief led them to distort it beyond recognition. “Finding a simple revelation of God, they… proceeded to debate about His properties… Some assert Him to be incorporeal; others maintain He has a body… Some think He is composed of atoms, others of numbers.”. Every one of these debates, in Tertullian’s eyes, was an unnecessary deviation introduced by human arrogance. God had already spoken – but man “too proud” to accept it had to add his own embellishments and speculations, thus muddying the water of truth.

This analysis flips the script on the philosophers’ pretensions: they called Christians ignorant, but Tertullian asserts that any wisdom the philosophers have came from God in the first place. They stole from God’s truth, then mangled it. Thus, their teachings carry a double guilt: theft and perversion of divine revelation. And this, Tertullian contends, was no innocent mistake either. It was instigated by a very real spiritual adversary.

Philosophy and Demons: Pagan Wisdom as Spiritual War

To Tertullian, the battle between Athens and Jerusalem – between pagan philosophy and Christian truth – was not merely an academic disagreement. It was a front in the spiritual war between God and the forces of evil. He openly declares that behind pagan religion and philosophy lurk demonic powers, manipulating human pride and curiosity to keep people from God.

This was a common belief among the early Christians: that the pagan gods were actually demons in disguise (cf. 1 Cor. 10:20). Tertullian takes it a step further by linking philosophers to demons as well. He notes, for instance, that Socrates, often hailed as the wisest of the Greeks, admitted to having a personal “daemon” (spirit) who guided him. Pagans thought this was a good thing—a sort of guardian spirit. Tertullian, however, says flatly: “Why not [believe it]? Since it is said an evil spirit attached itself specially to him even from his childhood – turning his mind, no doubt, from what was good." In other words, Socrates’ famous “inner voice” was, in the Christian diagnosis, a demon deliberately leading him away from God’s truth under the guise of enlightenment. And Socrates was not alone. “The philosophers acknowledge there are demons,” Tertullian writes; “Socrates himself [listened to] a demon’s will.” The poets too spoke often of intercourse with the gods and spirits. This was not fantasy, Tertullian warns, but demonic influence at work.

In Apology Chapter 22, Tertullian lays out a sort of demonology that explains a lot of the phenomena of pagan “wisdom.” He says that wicked angels and demons, since the earliest times, have dedicated themselves to the ruin of mankind. They inflict diseases, incite passions and vices, and—most insidiously—they counterfeit religious truth to ensnare souls. These spirits have remarkable abilities: “Their swiftness of motion is taken for divinity, because their nature is unknown,” he writes. For example, a demon (like the famous Pythian oracle spirit at Delphi) can race from one end of the earth to the other in an instant, gathering information. Then, through an oracle or a seer, it declares some secret as if by divine knowledge—amazing the listeners. In one case Tertullian mentions, the Delphic demon correctly stated that a distant king was boiling a tortoise and a lamb in a pot – a truth no human could have known at that moment. The gullible conclude, “Surely the gods (or the oracle) know all things!” But in reality, the demon simply spied the fact with preternatural speed.

Through such tricks, Tertullian says, demons “set themselves up as rivals of the true God, while they steal His divinations.” They had even been eavesdropping on the Hebrew prophets of old: “The purposes of God, too, they took up of old from the lips of the prophets… thus getting intimations of the future, they set themselves forth as if they were the authors of the things which they announced.” In short, demons plagiarize prophecy just as philosophers plagiarize truth! All with the aim of misleading people away from the one true God.

This demonic activity dovetailed with philosophy. Tertullian argues that the “doctrines of men and demons” are often one and the same. The demons use the philosophers as “rash interpreters” to spread error in the name of wisdom. After all, if blatant idol-worship fails to ensnare someone, a proud intellectual system might do the trick. The “doctrines of devils” (1 Tim. 4:1) need not be crude; they may come packaged in elegant Plato or stirring Stoic ethics. But if they divert a soul from Christ, the demons’ purpose is served.

Tertullian points out that even pagans recognized an overlap between philosophers and sorcerers: Pythagoras, for example, was reputed to have been schooled in Egyptian magic, and Empedocles and others dabbled in occult lore. Apollonius of Tyana, a Neopythagorean contemporary of Jesus, was essentially a wandering wonder-worker claiming secret wisdom—Christians saw him as demon-empowered. So Tertullian does not hesitate to suggest that when philosophers hit upon striking ideas or perform wonders, demons might be the source. As he quips, if a magician can call up a ghost or an apparition through occult ritual, how much more could a demon inspire a false teacher to spout a brilliant but soul-destroying new philosophy.

For Tertullian, the conclusion is stark: pagan philosophy is not merely human folly, but a form of spiritual captivity. It is aligned with demonic deceit, whether consciously or not. No wonder, then, that it is characterized by endless doubt, contradiction, and moral failures (Tertullian loved to point out the moral scandals of philosophers – from Plato’s being twice sold into slavery, to the drunkenness of Alexander’s tutor Aristotle, to the suicide of Zeno). The “gods of the nations” (Ps. 96:5) are demons, and those demons will gladly use either superstition or philosophy – Jupiter’s altar or Aristotle’s lyceum – to achieve the same end: the prideful exaltation of self and the rejection of God’s authority.

Poison in the Church: How Syncretism Infiltrated Early Christianity

Given Tertullian’s critique of philosophy, it’s no surprise that he was also alarmed by trends within the Christian movement to mix the gospel with pagan thought. He saw this as “syncretism” at best and heresy at worst. In his day, various teachers and sects arose, attempting to create a hybrid of Christian doctrine with Greek philosophy or other religions. Tertullian fought these distortions tooth and nail.

In his treatise Prescription Against Heretics, Tertullian flatly declares: “Heresies are themselves instigated by philosophy.” He then gives examples that were fresh in his time:

• The Valentinians, a prominent Gnostic sect, constructed elaborate theories of divine emanations (aeons) and cosmic fall – ideas clearly lifted from Platonic and Pythagorean speculation about metaphysical hierarchies. Tertullian notes that “Valentinus was of Plato’s school.” Indeed, the Gnostic idea of a distant first principle and successive emanations bears the stamp of Plato’s abstract “Ideas” and the Pythagorean love of mystical series. Valentinus essentially tried to blend Christianity with Plato, producing a “mottled” doctrine that deviated from apostolic truth.

• Marcion, another famous heretic in Rome, rejected the Old Testament and portrayed the God of Jesus as a completely different, higher deity than the creator God of the Jews. Tertullian associates Marcion’s ideas with Stoic philosophy: Marcion’s god was remote, impassible, unmoved by emotion or justice—much like the Stoics’ conception of the divine logos or the detached sage. Marcion also had a notion of the “body” being despised and no resurrection, which aligned with a general Greek disdain for matter. Tertullian quips that Marcion’s “better god” came from the Stoics’ ideal of apathy.

• Other errors: The denial of the resurrection of the flesh was popular among philosophers (who preferred the soul’s immortality only) – Tertullian says this “is taken from the aggregate school of all the philosophers.” The idea that matter is eternal (and thus a second God) was taught by some like Hermogenes – this comes straight from Stoic and Platonic conceptions of matter or primal hyle (and from Aristotle’s “unmoved movers”). The notion of a “god of fire” at the origin, which some heretics toyed with, obviously echoes Heraclitus. Even the use of dialectical arguments and endless questions by heretical teachers – Paul warns Timothy about “unprofitable questions” and arguments that spread like cancer (2 Tim. 2:17) – Tertullian lays at the feet of Aristotle, who “invented dialectics, the art of building up and pulling down, of constant quibbling”, which heretics use to obscure truth.

In short, every major heresy of the early centuries, Tertullian traces to a philosophical source. “From this source came the Aeons… from this source Marcion’s god… when matter is put on par with God, that’s Zeno; when one alleges a god of fire, there’s Heraclitus.” He even mentions Epicurean influence (the idea that the soul perishes, so no judgment to fear) being echoed in some heretical circles. This was an all-out indictment: pagan philosophy was the parent of Christian heresies. What the apostles had taught in purity, proud teachers later “adulterated” with Greek speculative ideas– just as the philosophers had adulterated the truth before.

Tertullian’s refrain, therefore, was to keep Athens out of Jerusalem. The Church must guard the “deposit” of faith delivered by Christ and the Apostles, and reject these mottled doctrines. The rule of faith, he said, does not bend to accommodate Plato’s or Zeno’s fancies. “See to it that no one takes you captive by philosophy and empty deceit, according to human tradition,” warned the Apostle Paul (Colossians 2:8) – a verse Tertullian eagerly passed on. For Tertullian, it was no coincidence that the first century of the Church immediately saw an influx of false teachings (like gnosticisms) that tried to marry the gospel to older philosophies. It was the same old prideful spirit at work. The devil, he would say, was trying the same trick on the church that he had on Greece: “Did God really say…? Perhaps there’s a higher knowledge, a philosophia, that you Christians are missing. Let me show you a different interpretation.” 

But Tertullian would roar back: No! Christianity has nothing to learn from those prideful systems. “Away with all attempts to produce a Christianity” blended with Stoicism or Platonism. Christ alone is the truth, and the moment you add Aristotle’s logic-chopping or Pythagoras’ numerology or Zeno’s fatalism to it, you’ve lost the truth and gained a lie.

He was so fervent on this point that later Christian thinkers found him a bit extreme. (After all, some others like Justin Martyr or Clement of Alexandria saw a value in Greek philosophy as a “preparation for the gospel.”) But Tertullian’s concern was purity of doctrine and the spiritual safety of his flock. From his vantage, every attempt to forge an intellectual alliance between the gospel and pagan thought had led to disaster – to bizarre heresies, splinter sects, and moral compromise. Thus, he believed his strict line was warranted. Pride was the common root of these syncretistic heresies, just as it was of the original pagan philosophies. And pride is not cured by indulging it further, but by repentance and faith.

Repeating the Old Deception: Modern Syncretism and the “One-World” Religion Agenda

Standing in the 21st century, nearly two millennia after Tertullian, we might fancy ourselves far removed from the world of Stoics and Gnostics. But are we? In truth, the same patterns Tertullian fought have re-emerged in new guises today. The names and terminology have changed, but the impulse to blend, dilute, or replace God’s revelation with human speculation is alive and well.

Consider the modern landscape of interfaith movements, New Age spirituality, and the push for a “one-world religion” or universal creed. In an era of globalization and pluralism, it has become fashionable to say that all religions are ultimately the same, that doctrine and truth claims don’t matter as much as mystical experience or ethical consensus. Many are attempting to create a syncretistic spiritual unity – a kind of neo-Babel project of building a heavenly city with our own intellectual bricks (cf. Gen. 11:4). Conferences are held celebrating the “harmony” of Christianity, Buddhism, Islam, and humanism. There are projects to draft a universal scripture by cherry-picking pieces from each faith. In some academic theologians’ circles, we hear that we must update or reinterpret Christianity to mesh with modern philosophy and science, even if that means discarding miracles, the uniqueness of Christ, or the authority of the Bible.

Tertullian would not be surprised. He would likely point his finger and say: “There – Athens is trying to colonize Jerusalem again.” The forms differ: instead of Stoic or Platonic philosophy, today we have perhaps secular humanism, scientism, or postmodern relativism. Instead of Gnostic emanations, we have New Age pantheism; instead of Marcion’s rejection of Scripture, we have “progressive” theologians who cut and paste the Bible according to current ideology. But underlying much of it is the same old presumption: that man’s reason or spiritual intuition can improve on God’s revelation, or even supplant it.

For example, the sentiment that “we don’t need doctrine or the Bible; we can each find God in our own way” is essentially a reprise of what the Gnostics and pagan philosophers claimed – that personal insight or mystical speculation was superior to the “simple” faith of the church. Tertullian’s retort that the truth is ancient and fixed and must be received, not invented, applies just as much now. “Nothing is so old as the truth,” he reminded the syncretists of his day, urging them to stick with what God had spoken from the beginning. Today, in a climate where novelty is often prized over orthodoxy, that reminder is urgent.

Moreover, the push for a universal religion often involves deliberately downplaying the exclusive claims of Christ and blending Christian worship with pagan or secular elements. This is exactly what Tertullian warned against when he objected to a “mottled Christianity” composed of bits of Stoicism, Platonism, and so forth. He would see today’s calls for Christians to merge into a generic global faith as just another attempt of Athens to wed Jerusalem – with Athens as the dominant partner. And he would say it’s motivated by the same thing: human pride and a restless curiosity that cannot bear the scandal of a distinctive, revealed truth. People don’t want to submit to the lordship of Christ as the one way; they prefer a mishmash that lets each person remain lord of their own beliefs. This is precisely the “self-sufficient reason” that Tertullian contrasted with humble submission to God.

One might also note that behind modern syncretism, spiritual forces may well be at work. If one believes (as Tertullian certainly did) that demons are real and active, it’s not hard to imagine that they have a vested interest in a one-world false religion. What could please the enemy of souls more than seeing humanity unite in a counterfeit worship that ignores the true God? The Book of Revelation speaks of an end-times deception uniting the kings of the earth against God, even a “false prophet” and an image that people are made to worship (Revelation 13, 16:13-14). Without diving into specific interpretations, we can say that Scripture foresees strong delusions drawing the world into religious error in the last days (2 Thess. 2:9-12). Modern interfaith universalism bears the fingerprints of that old deceiver who loves to whisper, “You shall not surely die… you shall be as gods, determining good and evil for yourselves.” It tells people what they want to hear – that they are wise enough to find or create truth on their own – and thereby repeats the primordial lie.

Tertullian’s counsel in such a time would be the same as it was in his: Stand firm in the apostolic truth. Do not yield the ground of Jerusalem to the sly intrusions of Athens. “Guard the good deposit” (2 Tim. 1:14) and reject “profane babblings and contradictions of what is falsely called knowledge” (1 Tim. 6:20). Christians must cling to revelation – humbly, faithfully – and reject the siren song of proud speculation.

The Sun’s Day vs. the Sabbath: Sun-Worship or True Christian Worship?

Sun-Worship and the Philosophical “One” (Monad)

Ancient pagan philosophy and religion often exalted the sun as the supreme deity – the singular One. In Greek Pythagorean thought, the concept of the Monad (the “One”) was revered as the ultimate principle of the universe. Notably, Pythagoras associated the number one with Apollo (the sun god), and he “worshipped the One [Monad]” even while acknowledging a plurality of lesser gods. In his teachings the divine Fire – effectively a cosmic representation of the sun – was identified with this Monad, the source of all life. This blending of philosophical monotheism with sun-worship laid a foundation in the Greco-Roman world: the sun was venerated as the visible symbol of the One God.

It is no surprise, then, that the Romans (heavily influenced by Greek thought) honored the sun in their religious culture. By the late empire, Sol Invictus (the Unconquered Sun) was hailed as a supreme god, and sun-worship cults like Mithraism were widespread. Sunday itself – literally “the Sun’s day” – became a focus of pagan reverence. The philosophical idea of unity (the One) found an easy analogue in the singular brilliance of the sun. Thus, exalting the “One” sun in the sky became synonymous with exalting the highest divine principle. The “venerable day of the Sun” was cherished among pagan Romans long before Christianity rose to prominence. In short, honoring the sun as the One true source was a hallmark of Roman pagan philosophy and practice.

From Sabbath to Sunday: A Historical Shift under Rome

According to the Bible, the divine seventh day (Saturday) was set apart by God as the holy day of rest and worship (Genesis 2:3, Exodus 20:8–11). Jesus Christ Himself – whom many Christians understand to be the same Lord who instituted the Sabbath in the Old Testament – observed and affirmed this seventh-day Sabbath. However, in the centuries after Christ, a dramatic shift occurred: the Roman Church replaced the Sabbath with Sunday. Superficially, this change is often justified by Christians as honoring Jesus’ resurrection, but a closer look at history suggests pagan influence was a driving factor.

Early Christian writers even had to address accusations that Christians were really sun-worshipers because of their Sunday gatherings. Tertullian, around 197 A.D., noted that some pagan critics believed “the sun is [our] god,” observing that Christians prayed toward the east at dawn and rejoiced on Sun-day. Tertullian defensively argued that Christians devoted Sunday to joy “for a far different reason than Sun-worship”, yet he admitted a “resemblance” between Christian practice and Rome’s own habits. He pointed out that just as Romans “devote the day of Saturn [Saturday] to ease and luxury” – while ignorant of the Jewish Sabbath – Christians devoted Sunday to worship. This resemblance was no coincidence; it highlights how entwined the Church had become with Roman custom. Rather than persist in “Jewish ways” (the original Sabbath), many early Christians in the Empire drifted toward the Roman pattern, distancing themselves from anything that appeared “too Jewish.”

The pivotal moment came in the fourth century. In 321 A.D., Emperor Constantine the Great – who had politically "embraced Christianity"– issued a civil decree establishing Sunday as a day of rest. Crucially, his law explicitly honored “the venerable day of the Sun” (dies Solis). Constantine, a former sun-worshiper, synthesized pagan and Christian practices to unify his empire. Historical records confirm that Constantine accommodated the pagans by officially accepting their sacred day, Sunday, in place of the Christian Sabbaths. “Constantine accepted their day of worship, Sunday, instead of the Christian Sabbath which had been observed by Jesus and His disciples,” as one historical summary notes. This edict did not cite Christ’s resurrection at all – it plainly honored the Sun’s day. In effect, the Roman Empire carried on its worship of the sun (the Monad) under the veneer of state-endorsed Christianity.

Multiple factors cemented Sunday observance in the Church thereafter. As waves of pagan converts flooded into an imperial Church, they brought with them long-held traditions of Sunday-festivity in honor of the sun. Church authorities, rather than resisting, often encouraged this continuity – it made conversion politically and culturally “convenient”. Over time, Church councils and theologians openly acknowledged that the Church had changed the day of worship. By the medieval period, Sunday was firmly established as “the Lord’s Day” in Christian tradition – yet its roots in sun-worship and Roman philosophy were largely forgotten or downplayed.

Resurrection Timing and the Lord of the Sabbath

Many Christians today defend Sunday worship by claiming Jesus Christ rose from the dead on Sunday morning. But a careful look at Scripture shows that this reasoning is, at best, a later justification – a “cop-out” that obscures the real influences of sun-worship. The Bible records that Jesus was already risen by early Sunday dawn, meaning the resurrection itself did not require a daytime Sunday celebration. For example, Matthew 28:1 (KJV) pointedly says: “In the end of the Sabbath, as it began to dawn toward the first day of the week,” the women came to the tomb. In other words, at sunset Saturday and into the pre-dawn hours of Sunday, the event had already occurred. Likewise, John 20:1 testifies that Mary Magdalene found the tomb empty “early on the first day of the week, while it was still dark”. By the time the sun actually rose on Sunday, Christ’s tomb was empty – He had risen sometime prior, essentially at the close of the Sabbath.

These Gospel details undermine the claim that Sunday daylight was the special moment of resurrection that would warrant a new holy day. The New Testament nowhere instructs believers to abandon the Sabbath because of the resurrection. In fact, Christ’s closest followers continued to observe the Sabbath after His death (e.g. Luke 23:56), and the apostolic church met on various days (including breaking bread on a Sunday evening in Acts 20:7) without pronouncing a new Sabbath. The common assertion “we keep Sunday to honor the resurrection” was never commanded by Jesus – instead, it became a convenient rationale as the Church drifted toward Sunday under Roman influence. It is telling that Scripture calls Jesus “Lord of the Sabbath,” not Lord of Sunday. “The Son of Man is Lord even of the Sabbath,” Jesus declared, reaffirming the sacred status of the seventh-day Sabbath (Saturday) which He created for humanity. Nowhere did He say He was Lord of the First Day. If anything, Christ’s words and example exalt the Sabbath: He kept it, taught on it, and claimed lordship over it – indicating it belongs to Him in a special way.

Thus, to truly worship Christ, one would honor the day He sanctified – the seventh day. Christ is the “Word made flesh” (John 1:14) who gave the Ten Commandments, including the command to “Remember the Sabbath day, to keep it holy.” Changing the worship day to Sunday – a move made by later human authorities – finds no endorsement in the life or teachings of Jesus. Rather, it mirrors the pagan philosophy that elevated the sun/monad in place of the Creator.

Returning to the Divine Seventh Day

In light of these facts, the theory holds strong: if the Roman Church (or any Christian body) truly centered its worship on Christ, the Lord of Scripture, it would not forsake the seventh-day Sabbath that He established. Substituting Saturday with Sunday was a product of Roman syncretism – the melding of pagan sun-worship (the venerable “One”) with Christianity, not a mandate from the Risen Christ. The appeal to the resurrection as justification for Sunday observance is a relatively flimsy after-the-fact argument; after all, Christ had already risen by the end of Sabbath according to Scripture. Meanwhile, He explicitly identified Himself with the Sabbath (“made for man” – Mark 2:27) as its rightful Lord.

Early in the faith’s history, compromises were made – “Christianizing” pagan practices to make conversion easier. Sunday-keeping was one such compromise, born from philosophical and political expediency. It allowed worship of the Son of God to be subtly merged with reverence for the sun in the sky. But Christ brooks no rival – “You shall have no other gods before Me” remains as true as ever. The sun is merely a creation, a “great light” made on the fourth day of Creation; the Sabbath was hallowed by the Creator Himself on the seventh day.

In the end, authentic Christianity calls believers back to the commandments of God over the traditions of men. That means honoring the day God called His own. The seventh day (Saturday) – not Sunday – is the “Lord’s Day” given by the Lord of the Sabbath. A church that claims to worship Christ yet clings to the Sun’s day in place of the Sabbath must confront this inconsistency. As history shows, Sunday sanctity owes more to pagan philosophy and Roman decree than to Christ’s word. True worshipers, seeking to worship the Father “in spirit and truth” (John 4:23), will recognize that the venerable day of the sun is a human substitution, whereas the Sabbath is the divine appointment. If Christ is truly the object of our worship, then obedience to His sanctified seventh day is the authentic response – anything less risks honoring a tradition rooted in the monad of sun-worship rather than the Son of God.

Tertullian’s story ends in paradox. A man of blazing conviction, he became increasingly disillusioned with what he saw as compromise and laxity in the church at Carthage. He was especially angry at bishops who, in his view, diluted discipline and tolerated sin. In his later years, he turned toward the Montanist revival, which emphasized strict moral discipline, prophecy and visions, the imminent return of Christ, and absolute purity of the church. The bishops branded Montanism heresy, but to Tertullian it was the “New Prophecy” that restored the Spirit’s authority — and when he spoke, the church ignored him.

For the rest of his life he wrote as a voice in the wilderness, separated from the institution he once defended. His followers, later called the “Tertullianists,” kept his writings alive in Carthage for nearly two centuries, until Augustine reports that they were eventually swallowed back into the broader church. Tertullian himself likely died between 220 and 240 AD, still outside the Catholic fold.

His legacy is as sharp-edged as his pen. He gave us language still used to describe the Trinity (trinitas), and yet he was never canonized as a saint. He defended the faith with unmatched brilliance, and yet he broke with the church in pursuit of greater purity. He stands as both a warning and a witness: proof that human pride and compromise can corrode the visible church, and proof that God still raises voices who refuse to bow. Tertullian’s life leaves us with a haunting question — will we repeat the errors of the bishops who ignored him, or will we heed his cry to return to the simplicity of Christ, uncorrupted by philosophy, unbent by pride, and untainted by the worship of the serpent and the stars?