The whole idea of faith is belief without proof; if God "proved" himself then we have proof, and no faith. Or something like that, is what all the religious people tell me.
No it's not. All the religious people you've talked to have gotten it wrong. Even Jesus asked his disciples to make their decision about him based upon what they had witnessed:
If God is real, and requires his followers to do all the anti-humanity acts in the various texts, that entity shouldn't be worshiped anyway.
Why not? How can you, in a universe without objective moral truth, say anyone should or shouldn't do anything and be able to have any legitimacy? The very best you can do is state a preference, but you can't make a moral judgement.
God is quite a violent entity; I'd rather have us go it alone than have some homicidal, all-powerful creature just waiting to burn me forever in hell because I mowed my lawn on a Saturday.
Yes, atheistic regimes have been peaceful & made the world a better place. *smh*