Suppose that religious impulses arose from a evolutionary nexus originally imposed as a maximal survival strategy by the presence of a larger more robust competing form of proto-human? We know that our ancestors were the more gracile of two forms of proto-human and that for 6-8 million years while our proto-human brains evolved, our greatest fear was that of being devoured by creatures like us but 3-4 time bigger.
Rather like the bottom of this scene of the Last Judgement at Chartres:



http://classics.uc.edu/~johnson/hum9...tres-south.asp