I'm going to have to leave you with this theory of yours lol. Altruism is biological in it's foundation and that's quite easy to prove as there have been several cultures devoid of any of the major religions you described that have exhibited significantly higher levels of altruism relative to let's say.... christianity. Spirituality may promote it, but again, it doesn't have the monopoly because it choses to reinforce it, generally, out of manipulation.
Finally, Hitler didn't murder all those Jews by himself, a nation full of christians stood by and participated. Of course there are other historical examples, but that would fill up another thread.
I missed you.