One small point:
In human history, slavery is not necessarily related to race or racism.
Quite a number of Native American groups took slaves. It was sufficient that they were members of a different culture/group (us vs. them). The bible mentions and condones slavery.
For most of human history, the folks next door were the ones battled with, and enslaved if they lost those battles. Those folks would have been of the same racial group as the attackers. They were of a different
cultural group.
It wasn't until Europeans started running around the world in boats that different races came into serious contact with one another. Slavery was well-established long before then.
Europeans were able to take slavery to wholesale levels, but they didn't invent it.
Religious belief does not constitute scientific evidence, nor does it convey scientific knowledge.