[@Disdain] That was meant for the previous post made by Meta but came out after yours. Anyway, couldn't aliens also be a plausible explanation? This being you call God, could as well have been a creature from a highly advanced alien race who came to guide are own that was still in it's infancy. I mean, you don't really know what God [b]is[/b] do you? For all anyone knows maybe it isn't even a being, maybe just an unknown force of the universe. 

The devil and the demons who defied it could be another race who started learning the way things worked, the secrets of the universe and for that they were expelled, sent away, maybe even exterminated. And all that was a warning to our own race. Hell, maybe the church was right to burn those books as they knew the real nature of God so they wanted to save humanity by hindering it's technological advancement. Just throwing it out there XD