Gnosticism

— The Word became flesh and dwelt among us. John 1:14

Gnosticism is a heresy, spreading through the church from the second century onward, that fused Christianity with Neoplatonic philosophy, pagan mythology, astrology, and Persian dualism into a system centered on gnosis, secret spiritual knowledge, as the means of salvation.¹ It taught that matter is evil, that the true God did not create the material world but left that work to a lesser deity, and that Christ came only in appearance, not in a real human body, since divinity could not unite with matter.²

Historical Origin

Gnosticism emerged in the second century as an attempt to absorb Christianity into a broader synthesis of Neoplatonic philosophy, Syrian and Phoenician mythology, Chaldean astrology, and Persian dualism.¹ Its central question was how the human spirit had fallen into bondage to matter and how it could be freed again. Since matter was the source of evil, Gnostic teachers reasoned, it could not have come from the true God; various Gnostic schools instead posited a lesser deity, the demiurge, standing between the supreme God and the visible world and identified with the God of the Old Testament.¹

Two early responses to Gnosticism shaped the church’s later theology in different ways. Irenaeus, Tertullian, and Tertullian’s contemporary Hippolytus opposed Gnostic philosophy outright, and Irenaeus’s own counter-theology, laid out in his Against Heresies, proved the more lasting: the unity of God, the identity of the God of the Old and New Testaments, creation out of nothing, and the two natures of Christ “are all clearly stated and maintained by Irenaeus over against gnosticism.”¹ Where Gnostic teachers appealed to inward, subjective spiritual insight as the mark of a true Christian, Irenaeus answered with objective, checkable criteria instead:

True knowledge is the teaching of the apostles and of the ancient community of the church in the whole world, and the stamp of the body of Christ in accordance with the successions of bishops to whom the apostles handed down that church that exists everywhere.³

The Alexandrian catechists Clement and Origen took a different approach, attempting to answer Gnosticism by building a rival, orthodox gnosis of their own rather than rejecting the category outright; Origen’s own system absorbed enough of the surrounding philosophy that it included, in Bavinck’s assessment, “a dualism of spirit and matter” of its own.¹

Some of the movement’s own literature survives directly: a cache of Gnostic-influenced texts discovered at Nag Hammadi, Egypt, in 1945 included the Gospel of Thomas, a sayings-collection whose “strong Gnostic flavor,” including its interest in Jesus as a teacher who leads disciples to “find the divine spark within” themselves rather than a Jesus who demonstrates his own deity, is itself part of the scholarly case for dating the work to the mid-second century, later than and dependent on the four canonical Gospels.⁴

Core Tenets

Within this dualist framework, Gnostic teachers held that various “aeons” proceed from the true God for the purpose of liberating spirits trapped in matter, culminating in an aeon identified with Christ. Salvation itself came through gnosis (knowledge) joined with ascesis (ascetic discipline): pistis, ordinary faith, might suffice for the unlearned, but gnosis belonged to the truly spiritual, who alone could grasp their own divine origin. Gnostic teachers defended this system by reading Scripture allegorically, so that its own mythology could be presented as Scripture’s hidden meaning.¹

This dualism between spirit and matter made a genuine incarnation impossible to accept, so Gnostic Christology took several different forms, all denying that God the Son truly took on human flesh.² Bavinck catalogs the range: some Gnostics raised philosophical objections to Christ’s true humanity outright; Valentinus taught that Jesus brought “a glorious spiritual body from heaven which only passed through Mary like water through a conduit”; Apelles held that Christ assumed a “phantom body” that he shed again at his ascension.² Basilides took yet another route, holding that a real human Jesus was united with the divine at his baptism, though his own followers went on to reduce Christ’s body to “a seeming one,” with no genuine suffering or death.⁵ This Christological strand of Gnosticism is usually identified with Docetism, from the Greek for “to seem.”

Confessional and Biblical Response

Scripture makes confessing Christ’s coming “in the flesh” the test of true and false spirits (1 John 4:2-3; 2 John 7), and treats denying it as being not merely mistaken but “anti-Christian” (1 John 2:22).² Against the Gnostic claim that Christ’s body was illusory or merely passed through Mary, John writes that “the Word became flesh and dwelt among us” (John 1:14).

The Second Helvetic Confession names the same error: “the flesh of Christ was neither imaginary nor brought from heaven, as Valentinus and Marcion wrongly imagined.”⁶ The Second London Baptist Confession states the positive doctrine Gnostic Christology denies, without needing to name Gnosticism itself: the Son of God

did, when the fullness of time was come, take upon him man’s nature, with all the essential properties and common infirmities thereof, yet without sin… so that two whole, perfect, and distinct natures were inseparably joined together in one person, without conversion, composition, or confusion; which person is very God and very man.⁷

Bavinck draws out why this mattered pastorally as much as doctrinally: the church’s early rejection of every docetic Christology, ancient or modern, rests on the conviction that “what is not assumed is not saved.”² If Christ did not truly take on a real human body, he did not truly redeem one.

Modern Forms

Strong traces a historical line from Gnosticism to Manichaeism, noting that other scholars called Manichaeism “a compound of Gnosticism and Parseeism” or “the fruit, acme, and completion of Gnosticism,” while distinguishing the two by their relation to the church: “Gnosticism was a heresy in the church; Manichaeanism… was an anti-church.”⁸

A 2025 Themelios article by Meagan Stedman argues for a more contemporary connection. Surveying Gnostic primary texts such as the Apocryphon of John, the Gospel of Thomas, and the Gospel of Philip, alongside Tertullian’s own response to Gnostic anthropology, Stedman concludes “it is appropriate to make a nuanced comparison between the anthropology of ancient Gnosticism and that assumed by the contemporary transgender movement,” citing Oliver O’Donovan’s and Nancy Pearcey’s own use of the same comparison.⁹ The point of connection is the shared anti-cosmic dualism: just as Gnostic texts pitted a “true” inner self against the material body it merely inhabits, Stedman argues that transgender anthropology likewise treats the physical body as separable from, and secondary to, an inner, “authentic” self.⁹

Related Doctrines

References

Herman Bavinck, Reformed Dogmatics: Abridged in One Volume, ed. John Bolt (Grand Rapids: Baker Academic, 2011), chap. 2, “The History and Literature of Dogmatic Theology.” ↩ ↩² ↩³ ↩⁴ ↩⁵ ↩⁶
Bavinck, Reformed Dogmatics: Abridged in One Volume, chap. 14, “The Only Begotten Son of the Father.” ↩ ↩² ↩³ ↩⁴ ↩⁵
Ronald E. Heine, Classical Christian Doctrine: Introducing the Essentials of the Ancient Faith (Grand Rapids, MI: Baker Academic, 2013), chap. 12, “I Will Build My Church,” 129-142: “True knowledge is the teaching of the apostles and of the ancient community of the church in the whole world, and the stamp of the body of Christ in accordance with the successions of bishops to whom the apostles handed down that church that exists everywhere” (Irenaeus, Against Heresies 4.33.8). ↩
Michael J. Kruger, Canon Revisited: Establishing the Origins and Authority of the New Testament Books (Wheaton, IL: Crossway, 2012), chap. 8, “Problem Books and Canonical Boundaries.” ↩
Augustus Hopkins Strong, Systematic Theology: A Compendium and Commonplace-Book Designed for the Use of Theological Students, vol. 2 (Philadelphia: The Griffith & Rowland Press, 1907), 379. ↩
The Second Helvetic Confession (1566), “Christ Is True Man, Having Real Flesh.” ↩
The Second London Baptist Confession of Faith (1689), chap. 8, “Of Christ the Mediator,” para. 2. ↩
Strong, Systematic Theology, vol. 2, 380. ↩
Meagan Stedman, “‘Ancient Gnosticism in New Garb?’ Gnostic Anthropology, Transgenderism, and a Response from Tertullian,” Themelios 50, no. 1 (2025): 28-40. ↩ ↩²