Christianity is pro-slavery
This just show's me that you don't understand Christianity. Because people used something to further their own agenda and prejudice does not automatically mean that religion justify's the said act. And it does not.
those three religions have helped spread suffering in this world.
So first Christianity and now two more under the bus, let me guess one of them is Islam?
but at least, without religion, the bigots wouldn't act like they have the moral high ground.
Okay now you sound really biased, since when do you have to be religious to be a bigot? You don't is the answer.
And in your previous statement you stated that Roman's did not have a problem with anyone yet you neglected to mention that they had slaves, some of which they would force to kill each other in the gladitorial ring. You also failed to mention how many nations the Romans oppressed and utterly crushed to simply further their territorial gain.
Dude, you just destroyed that guy haha.