It's book My Dad read about a boy who discovers a door to a different dimension. On his quest he realizes he used to be GOD and was banished to this lower dimention by the Devil during an epic battle that he had lost a long time ago. The boy begins to grow stronger and travels through several more dimentions until he meets up with the Devil and Battles it out for his right to claim his rightfull place as GOD.
-ANYBODY???
-ANYBODY???