An esoteric cult of divine knowledge (a synthesis of Christianity, Greek philosophy, Hinduism, Buddhism, and the mystery cults of the Mediterranean), which flourished during the 2nd and 3rd centuries and was a rival to, and influence on, early Christianity. The medieval French Cathar heresy and the modern Mandean sect (in southern Iraq) descend from Gnosticism.

Gnostic 4th-century codices discovered in Egypt in the 1940s include the Gospel of St Thomas (unconnected with the disciple) and the Gospel of Mary, probably originating about AD 135. Gnosticism envisaged the world as a series of emanations from the highest of several gods. The lowest emanation was an evil god (the demiurge) who created the material world as a prison for the divine sparks that dwell in human bodies. The Gnostics identified this evil creator with the God of the Old Testament, and saw the Adam and Eve story and the ministry of Jesus as attempts to liberate humanity from his dominion, by imparting divine secret wisdom.