The doctrine of salvation by knowledge. This definition, based on the etymology of the word (gnosis knowledge, gnostikos, good at knowing), is correct as far as it goes, but it gives only one, though perhaps the predominant, characteristic of Gnostic systems of thought.

Whereas Judaism and Christianity, and almost all pagan systems, hold that the soul attains its proper end by obedience of mind and will to the Supreme Power, i.e. by faith and works, it is markedly peculiar to Gnosticism that it places the salvation of the soul merely in the possession of a quasi-intuitive knowledge of the mysteries of the universe and of magic formulas indicative of that knowledge.

Gnostics were people who knew, and their knowledge at once constituted them a superior class of beings, whose present and future status was essentially different from that of those who, for whatever reason, did not know. Many Gnostics are dualists believing in two forces, good and evil. The adepts strive to achieve the gnosis or depth of knowledge. It is remarkable how resilient is this line of thought.

With the growth of the New Age Movement, Gnostics have a new lease on life.