Well, it comes up in His Dark Materials (trilogy by Phillip Pullman (I think)), but basically here is what he said happened:
God was the first angel to come into existence. He was nothing special, aside from the fact that he was first. When other angels came to exist, God said "O, I made you, because I am all powerful", and basically tricked every angel into believing He created them. Lucifer, another angel, discovered the truth, and spread the word. Soon, heaven was split in two: those who sided with God, and those who sided with Lucifer. God's faction won, and cast Lucifer and his faction out of the kingdom.
More simplisticly, it's "God's a liar and Lucifer is correct". Thoughts?