History of gnostics date back to ancient greece, where gnosticism evolved as course of thinking of Plato, trying to describe world as dualistic battle between good and evil. First gnosticists believed that there are 2 gods ruling the world - one "big" god which controls all universe and minor "god" which controls humanity, known as Demiurge. They also believed in other minors gods, but worshipped the "big" god as the symbol of all universe. They also believed in power of wisdom and that the world can only be understood with power of mind.
In middle ages, the conceptions changed slightly, and gnostics began believing Demiurge is evil, personified with Devil, which traps humanity in sin, and the only way of liberation is through death, as the spirit is pure and the body is flawed. By leaving the body, only the pure soul remains. They also believed by learning aspects of god they can achieve the enlightment - the Gnosis - which is what christians would call "redemption", but achieved on earth, not with good deeds but with heading toward divine wisdom.
Gnostics have organised their churches, becoming slightly more like christians, with time. They seen three natures of God - which now became based on God described in Bible - the Father (which represents the universe), the Son (logos, which represents Gnosis) and the Holy Spirit (sophia, which represents wisdom).
The first symbol of gnostics was a cross used nowadays by polish skinheads...
(I would draw pic but it deson't display it right)
