"Brain pain". I like that phrase, it's catchy.
It must have happened at some time in our evolutionary development that our increased capacity to think left an uncomfortable void in our minds as respect to the outward world.
I disagree with certain points like,
"All other gods of other tribes are the false gods and the tribe's god is reason to commit genocide of other tribes"
First, there were many religions in the past that accepted the idea of multiple gods even those of their enemies. Whenever there was a war the strongest god - hopefully theirs - would defeat the other nation's god.
As for genocide, that was bound to occur regardless of religion or lack of religion. It's based on a totally different set of behavior. Any commands for genocide that "the god" gave were just projections of the human imagination which seeks to justify non religious behavior by creating divine decrees.