Part of the Casswiki article series Esoterica
For the series of books written by Boris Mouravieff, see: Gnosis (book trilogy)
Gnosis is a greek word meaning knowledge, and as a loanword it is mostly used when speaking of esoteric matters. The term has a connotation of experiential, lived or revealed knowledge as opposed to information acquired second hand, from books for example.
Gnosticism refers to a group of spiritual movements of the early Christian era, later judged heretical. There was a revival of Gnosticism between the 11th and 13th centuries, starting in Bulgaria with the Bogomiles and continuing in Southern France with the Cathars, also known as Albigensians.