From Lost Christianities:

Gnostic Christians varied widely among themselves in basic and fundamental issues. But many appear to have believed that the material world we live in is awful at best and evil at worst, that it came about as part of a cosmic catastrophe, and that the spiritual beings who inhabit it (i.e., human spirits) are in fact entrapped or imprisoned here. Most of the people imprisoned in the material world of the body, however, do not realize the true state of things; they are like a drunk person who needs to become sober or like someone sound asleep who needs to be awakened. In fact, the human spirit does not come from this world; it comes from the world above, from the divine realm. It is only when it realizes its true nature and origin that it can escape this world and return to the blessed existence of its eternal home. Salvation, in other words, comes through saving knowledge. The Greek term for knowledge is gnosis. And so these people are called Gnostics, “the ones who know.” But how do they acquire the knowledge they need for salvation? In Christian Gnostic texts, it is Jesus himself who comes down from the heavenly realm to reveal the necessary knowledge for salvation to those who have the spark of the divine spirit within.