It’s widely known that the Bible contains many passages which seem to implicitly condone slavery. For example, Exodus 21, which gives various rules for slavery including the rule that Hebrew slaves are to be freed after six years, or the infamous law from Leviticus that says you can only own foreigners as slaves. Then there are the various places in the Epistles where slaves are told to obey their masters (e.g. Ephesians 6:5, Colossians 3:22, 1 Peter 2:18).
What Christians often say about this is that God was making the best of a bad situation, and if he had started off giving sinful humans a command not to have slaves at all, no one would have listened. So instead he gave some commandments to limit the severity of slavery, which was better than nothing. That doesn’t mean God approves of slavery. And the stuff about slaves obeying their masters can be interpreted in line with the stuff about turning the other cheek, and walking a second mile when forced to walk one mile.
Seriously, why don’t more people notice this?