Gnosticism is an ancient christian sect. They believe that god created the universe, but this is a kind of pocket dimension created by an evil/misguided lesser being called the demiurge and we're all trapped here. They believed that through prayer and meditation you could achieve an enlightened state and exit the material realm upon death.

Incidentally this wasn't an idea that originates in early christianity, it's the core of most native european religions, and possibly eurasian ones in general.

The gnostics categorised people in three tiers (hylics, psychics and pneumatics). The hylics are the lowest of the three and are trapped in material thought, thinking solely about pleasure and pain. The psychics are those who are on the path to enlightenment and the pneumatics are those that have achieved it.