Gnosticism was a Middle Eastern religious and philosophical orientation that grew strong in the 1st century CE, exercising strong influence on Judaism and Christianity and at times representing a strong and competing theology. The gnostic tendencies in both these two religions were defeated in the 2nd century, but gnosticism survived for centuries in other religions.
The name comes from the Greek word for "knowledge," and suggests a belief that salvation comes from insight in secret knowledge. Gnosticism also assumes that humans have a capacity to discover truths with the aid of intellect alone.
Gnosticism is furthermore recognized for its dualism, which is the theory that everything is to be understood within the tension existing between two powers or qualities; light, the good or responsible; and darkness, the evil or the irresponsible. In this dualism, humans play a role, but they are of minimal importance within the great cosmic battle.
Even in modern times, central elements of Gnosticism is found in living religions: Isma'ilism. This religion is officially counted as belonging to Shi'i Islam, but the acceptance of this is linked with the need for protection within the Middle Eastern phenomenon known as taqiyya. Another religion with gnostic elements are the Mandeans.
Central figures, religions and writings of Gnosticism include Simon Magus, mentioned in the New Testament; elements in the gospel of John in the New Testament; the extinct world religion, Manichaeism; the still existing religions of the Mandeans and the Isma'ilis; and 2nd century teachers like Basilides and Valentinus. Some systems originating outside the Middle East have adherents in the region today, and include gnostic elements, like the Masonry and the American sect, the Church of Christ Scientist.