“The Gnostics (also called Manichees) postulated that there were two gods -- the Christian God of goodness and light, and an evil anti-God of darkness. This theory proved an easy explanation of why there was evil in the world. It was rejected by Catholic Christianity in favor of the monotheistic view that there was one God who created only goodness. Evil was sin, a rebellious falling-away from God, a perversion of His goodness. This was the foundation of the evolving Christian concept of Satan.”