Call me ignorant, but what is the difference? What exactly is Gnosticism?
Gnosis was an ancient heresy as old as apostolic Christianity.
Gnosis postulated that the God of the Old Testament and the God of the New Testament were two different gods. The first, the God of Creation, of "thou shalt not"'s was a lower god, the "demiurge". The higher New Testament god of love and forgiveness was the "aeon" who dwelt in the "pleuroma". By freeing yourself from laws and restrictions you could seek your own truth, your enlightenment, your "gnosis" (the word means knowledge in Greek. Not factual knowledge. Experiential knowledge.).