Check out Exodus 21:16
“Whoever steals a man and sells him, and anyone found in possession of him, shall be put to death.
So God doesn't want us to steal slaves or work people against their will, which is generally what slaves were. The word used for slaves in the Bible was very different, it involved allowing them to choose to work or leave, and they were also fed, and given a home. And you also need to remember that the slaves that were not given that choice were people they captured from nations that practiced idolatry, killing babies, etc. So it was either like a prisoner of war thing, or a person that decided to work for them. And I think it is pretty just to force someone who burns babies to work against their will, right? Wouldn't that seem kind of just?
First of all, if we did everything that people in the Bible did, we would murder, do adultery, curse, fornicate, etc. You're right, but we aren't supposed to follow what people do, we follow what God says. And God says not to have slaves, not to commit incest, fornicate, etc. And also, if you guys really think that God wants people to have slaves, i advise you read a book called "Is God a Moral Monster" by Paul Copan. It's a great book, and addresses seemingly pro-rape, pro-slave behavior. But the definition and culture of slavery was very different back then, I think you guys should look into it. It's quite interesting. Also this is a good meme my man.