I'd actually argue the opposite. Religion reigns in bad people. Talk to a religious person, wait until you hear them say something like, "but if there's no god and no afterlife, what's to stop people from murder and rape?" That's all that's holding them back from total anarchy, the threat of eternal suffering and damnation, only for some it's still not enough.
You're very good at strawman. I didn't say communism is atheism. However, you'll find that many communist regimes were atheistic. I'll give an example for atheism and secularism.
All the secular colonial states that have taken over other countries. Plus, the issues that continue to this day. Take the middle east for example and the lines drawn on purpose to keep the region destabilized. Or take francophone Africa which to this day suffers from Frances control over the region through dictators.
I don't deny there was crusades or that there was wars inspired or motivated by religion. I never said anything of sorts in my original comments. You're only assuming it.