Can you imagine a world without land? Resources? Opinions? It won't make a difference other than what they base their decision on. Hitler after all sought power and ethnic cleansing and wasn't really a practicing Christian. Hate was his downfall and it was rooted in racism and a lust for power. Was Chairman Mao a religious zealot? Stalin? Evil is a part of human nature regardless of whatever label is placed upon the reason for acting.
How about we imagine a world of free people and not totalitarian, socialist governments that took around 200+ million people off the face of the Earth in the 20th century. Religion had little if anything to do with those atrocities.
Socialism is not the issue, regardless of your definition of "socialism".
Racism, and all the other issues can come out of people regardless of whether socialism is part of it or not.
Nothing would exist without a creator, because something can't come from nothing. Believing God exists and created something is infinitely more plausible than nothing spontaneously producing something. So, if there was no religion, and therefore no God, then there wouldn't be an Earth to compare to this Earth, nullifying the question altogether.
Except God doesn't come from religion. Religion comes from God.
Even if I don't believe in you, that doesn't mean you cease to exist. Suppose for whatever reason, that God didn't reveal himself to man, and we developed without knowing anything about God. What would that world look like?