The Gnostics followed a variety of religious movements that stressed gnosis or knowledge, especially of one’s origins. Cosmological dualism was also a feature of the system—opposed spiritual worlds of good and evil. The material world was aligned with the dark world of evil.

No one is certain of the origins of Gnosticism. Some believe it was rooted in a heretical group within Judaism. Supporters of this theory cite The Apocalypse of Adam and The Paraphrase of Shem as early Gnostic documents revealing Jewish origins. Others give it a Christian context. An incipient form may have infiltrated the church in Colosse. Or it may have had a totally pagan root. During the second through the fourth centuries it was addressed as a major threat by such church fathers as Augustine, Justin Martyr, Irenaeus, Clement of Alexandria, Tertullian, and Origen.

Irenaeus’s book Against Heresies provides extensive treatment of what Gnostics believed. Three Coptic Gnostic codices were published. Two were discovered in Nag Hammadi, Egypt in 1945. Codex Askewianus contains Pistis Sophia and Codex Brucianus contains The Book of Jeu. Best known among the Nag Hammadi documents is the Gospel of Thomas. A third work from this period, Codex Berolinensis, was found elsewhere and published in 1955. It contains a Gospel of Mary [Magdalene], a Sophia of Jesus, Acts of Peter, and an Apocryphon of John. The first translation of a tractate, The Gospel of Truth, appeared in 1956, and a translation of fifty-one treatises, including Gospel of Thomas, appeared in 1977.

The early fathers of the church held that Gnosticism had first-century roots and that Simon the Sorcerer of Samaria (Acts 8) was the first Gnostic. According to church fathers, Simon practiced magic, claimed to be divine, and taught that his companion, a former prostitute, was reincarnated Helen of Troy. Hippolytus (d. 236) attributed the Apophasis Megale to Simon. Simon’s disciple, a former Samaritan named Menander, who taught in Syrian Antioch near the end of the first century, taught that those who believed in him would not die. That claim was nullified when he died.

At the beginning of the second century, Saturninus (Satornilos) asserted that the incorporeal Christ was the redeemer denying that Christ was really incarnated in human flesh. This belief is shared with docetism. In this period Cerinthus of Asia Minor was teaching adoptionism, the heresy that Jesus was merely a man upon whom Christ descended at his baptism. Since Christ could not die, he departed from Jesus before his crucifixion. Basilides of Egypt was called both a dualist by Irenaeus and a monist by Hippolytus.

One of the more controversial, though atypical, Gnostics was Marcion of Pontus. He believed that the God of the Old Testament was different from the God of the New Testament and that the canon of Scripture included only a truncated version of Luke and ten of Paul’s Epistles (all but the pastoral Epistles). His views were severely attacked by Tertullian (ca. 160s—ca. 215). Marcion became a stimulus for the early church to officially define the limits of the canon.

Valentinus of Alexandria was another prominent Gnostic. He came to Rome in 140 and taught that there were a series of divine emanations. He divided humanity into three classes: (1) Hylics or unbelievers, who were immersed in material and fleshly nature; (2) psychics or common Christians, who lived by faith and pneumatics; and (3) spiritual Gnostics. His followers included Ptolemaeus, Heracleon, Theodotus, and Marcus. Heracleon’s interpretation of John is the first known New Testament commentary.

Gnostic-like beliefs persisted into the fourth century. Among the late manifestations was Manichaeism, a dualistic cult that trapped Augustine in his pre-Christian life. Against it he wrote many treatises, which are collected in The Anti-Manichaean Writings in the Ante-Nicene Fathers.

Since Gnosticism lacked a common authority, it encompassed a variety of beliefs. Central to many, if not most, were:

Gnosticism as an organized movement acknowledging its source all but died. The sole surviving remnant is in southwestern Iran. However many Gnostic teachings live on among new agers, existentialists, and Bible critics. The revival of interest in the Gospel of Thomas by the Jesus Seminar is a case in point. There is also a tendency, even among some evangelical scholars, to deny the physical nature of the resurrection. However, Gnosticism lives today in the New Age Movement in an extensive way.

Gnosticism was thoroughly critiqued by the early church fathers, especially Irenaeus, Tertullian, Augustine, and Origen, though Origen bought into some of their views.