The rationalist explanation would be that gods are overblown ancestors. If one says, "The ancestors taught us how to plant grain and raise sheep and cattle," that sounds far less, uh, numnious.

However, I'm pretty sure I told you about a vision I had in 1989 (I won't describe the circumstances publically), in which it was basically revealed to me that there was an "alien invasion" about 10,000 years ago, wherein humankind was infected with a kind of virus that led to civilization. I'm not sure I "believe" that, but it may not be functionally that far from the truth. I've seen other versions of this concept, for example in the very whacked-out Transmitter to God by Rhawn Joseph.