The heresy of Gnosticism (Greek: γνωστικός,  ‘having knowledge’) is a collection of various religious groups that emphasized personal spiritual knowledge (gnosis) above the orthodox teachings, traditions, and authority of the Church. While the orthodox Christian understanding of salvation dealt with the concepts of sin and repentance, Gnosticism taught that salvation was gained through enlightenment by way of a secret knowledge that could only be found within Gnostic sects.  Gnosticism was also dualistic, teaching that there were at least two distinct deities; a supreme, hidden God and a lesser malevolent god who was responsible for creating the material universe. Consequently, Gnostics considered the material world to be flawed or evil. Christ, in the Gnostic tradition, was not truly God, but merely a created being who was the lowest of the aeons; a group of semi-divine beings between God and man who were given power by a higher aeon. Views on Christ’s nature varied from sect to sect, but many sects held that, because created matter was evil, Christ‘s humanity was merely an illusion and therefore Christ only appeared to die.  In order to deny the reality of Jesus’ body and the gospel records of Christ walking, eating, and sleeping, they resorted to the theory that He only appeared to do these things:

“Jesus took them all by stealth, for he did not reveal himself in the manner in which he was, but it was in the manner in which they would be able to see him that he revealed himself.” [The Gospel of Philip, 57.]

“I will tell you another glory, brethren: sometimes when I meant to touch him I encountered a material, solid body; but at other times again when I felt him, his substance was immaterial and incorporeal . . . as if it did not exist at all.” [Acts of John 93, in Elaine Pagels,  The Gnostic Gospels New York: Vintage, 1981, 88.] 

Gnosticism, which was apparently already well known in the first century, “piggybacked” on the quickly growing early Christian faith.  The Apostle John even seems to refute Gnostic claims in his first Epistle;

“the Word of Life, that which was from the beginning, which we have heard, which we have seen with our eyes, which we have looked upon and touched with our hands” (1 John 1:1)

“the Life was made manifest, and we saw it” (1 John 1:2).

”By this you know the Spirit of God: every spirit which confesses that Jesus Christ has come in the flesh is of God” (1 John 4:2). 

In 107 A.D., Ignatius Theophorus, Bishop of Antioch, who was rumored to have been the little child placed among the apostles by our Lord (Matt. 18 :2), wrote a series of letters to Churches while on his way to Rome.   To the Church in Tralles, a town in Asia Minor, he wrote:

“Stop your ears, therefore, when anyone speaks to you at variance with Jesus Christ, who was descended from David, and was also of Mary; who was truly born, and did eat and drink. He was truly persecuted under Pontius Pilate; he was truly crucified, and truly died, in the sight of beings in heaven, and on earth, and under the earth. He was also truly raised from the dead . . . But if, as some that are without God, that is, the unbelieving, say, that he only seemed to suffer (they themselves only seeming to exist), then why am I in bonds? Why do I long to be exposed to the wild beasts?”[ Ignatius of Antioch,  Epistle to the Trallians, 8-9 in  The Ante-Nicene Fathers, vol 1.]

Despite these early efforts by orthodox Christianity to curb the errors of Gnosticism, Gnostic groups and their writings flourished in the second century. Gnostic texts proliferated and their authorship was often ascribed to an apostle in order to lend them greater credibility, for example; the  Book of Thomas the Contender, the Apocryphon of James, the Apocryphon of John, the Acts of Peter and the Twelve Apostles, the Apocalypse of Paul, etc.  These texts furthered the notion that the person of Christ was merely a phantasm and would explain away the Crucifixion as just another illusion; one that Christ Himself laughed at:

“It was another who drank the gall and the vinegar; it was not I . . . It was another upon whom they placed the crown of thorns. But I was rejoicing in the height over . . . their error, of their empty glory. And I was laughing at their ignorance.” [The Second Treatise of the Great Seth, 56, Roger Bullard, trans., in  The Nag Hammadi Library. ]

“The Savior said to me, ‘He whom you saw being glad and laughing above the cross is the living Jesus. But he into whose hands and feet they are caving the nails is his fleshly part, which is the substitute. They put to shame that which remained in his likeness. And look at him, and me!’” [ The Apocalypse of Peter, 81, Roger Bullard, trans., in The Nag Hammadi Library. ]

While these Gnostic texts are undebatably 2nd and 3rd century works, perhaps the most well known Gnostic text is the Gospel of Thomas which is striking because of its very ancient forms of some of the sayings found in the canonical Gospels.  Parts of it probably date from the first century. Helmut Koester maintains, along with many other scholars of Gnosticism and early Christianity, that the sayings in the Gospel of Thomas are just as old or even older than the canonical Gospels.[ Helmut Koester, The Gospel of Thomas, introduction. In The Nag Hammadi Library, 117. ].  Some scholars have even proposed it to be the hypothetical “Q Source”; the source hypothesized to explain the sayings of Jesus that are reported by Matthew and Luke but are absent from Mark.

The Gospel of Thomas, therefore, presents Protestants with a problem: why should it be denied a place in the canon?  It is ancient and has a good a claim to being just as ancient as the biblical gospels.  It claims to be of apostolic authorship or at least could have come from the Apostle Thomas in a way similar to the Gospel of Luke originating with Paul and the Gospel of Mark with Peter.   The argument that most Protestants would likely make against it is the unorthodoxy found in the Gospel of Thomas, based off the fact that Paul and John openly reject Gnostic ideas in the New Testament. The problem with this  sola scriptura-based argument is that it’s circular:  Thomas is rejected because it conflicts with New Testament orthodoxy, yet New Testament orthodoxy is defined by a canon that excludes Thomas. Why should the works of Paul and John take precedence over those of Thomas, who was just as much an apostle as they were?  Why shouldn’t Thomas be placed in the Bíblical canon rather than the works of John or Paul (who wasn’t one of the original Apostles)?

The only way out of this argument is to appeal to tradition.  The earliest extant post-New Testament document, the late first-century Epistle of Pope Clement I to the Corinthiansquotes extensively from the canonical Gospels, but shows no trace of Thomas. Likewise, early 2nd century writers such as Ignatius of Antioch, Polycarp and Justin Martyr, also show no signs of it.  Irenaeus of Lyons completely rejects the notion that the Apostles passed on any hidden knowledge;

“It is within the power of all, therefore, in every church, who may wish to see the truth, to contemplate clearly the tradition of the apostles manifested throughout the whole world; and we are in a position to reckon up those who were by the apostles instituted bishops in the churches, and to demonstrate the succession of these men to our own times; those who neither taught nor knew of anything like what these heretics rave about. For if the apostles had known hidden mysteries, which they were in the habit of imparting to ‘the perfect’ apart and privily from the rest, they would have delivered them especially to those to whom they were also committing the Churches themselves.” [Irenaeus, book III, chapter iii.]

The use of the word heresy by Irenaeus in his work Contra Haereses (Against Heresies) to describe Gnosticism became the term used to denote any unorthodox teaching that delineated from Sacred Tradition and the teaching authority of the Church Magisterium.


  • Papandrea, James L. (2016). The Earliest Christologies: Five Images of Christ in the Postapostolic Age. InterVarsity Press.
  • Pagels, Elaine (1979), The Gnostic Gospels, New York: Vintage Books
  • Helmut Koester, The Gospel of Thomas, introduction. In The Nag Hammadi Library, 117

Extant Texts:

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