@Addison
In the Bible, Israelites became slaves to one another, not through kidnapping or a lower societal birth, but because of debt or poverty.
According to most Old Testament slave apologists, selling one self into slavery during the time of the Israelites was a way to pay off debt. So, Israelites who owed money, goods or land, might sell themselves into slavery and even their children to pay off a debt.
If this is not condoning slavery, I don’t know what is. Because you will never read an absolute condemnation of slavery in the Bible.
For many historians, nothing was as bad as Chattel Slavery imposed on African or Freed Blacks in the U.S. This type of Chattel Slavery was full of cruelty, inhumanity and capricious violence.
But slaves to Israelites, who were supposed to be treated as hired hands, were not to be badly treated. If an Israelite slave was given a foreign woman as a wife and she birthed children for him, the foreign wife could not be freed, nor her children. That is slavery with no end.
This is how the Bible explains this when it came time to free an Israelite slave:
“If his master gives him a wife and she bears him sons or daughters, the wife and her children will become her master’s and he will go out by himself.” (Exodus 21: 4).
Now, pay attention to that verse. The so-called Master could GIVE the slave a wife. Think the woman or the children had any choice in the matter?
And as I mentioned in a previous post, some Israelite slave owners did mistreat their slaves, which is why laws had to be written about this.
“If a man strikes the eye of his slave man or the eye of his slave girl and he destroys it, he is to let the slave go free in compensation for his eye. And if he knocks out the tooth of his slave man or of his slave girl, he is to let the slave go free in compensation for his tooth.” (Exodus 21:26, 27)
In the Bible, slavery persisted into the days of the Roman Empire because Philemon, a disciple of Jesus, the Nazarene, owned a slave named Onesimus. (Philemon 16)
Even in the first century, slaves weren't treated spectacularly well as evidence by Paul's warnings to some folks who were apparently following his teachings. "And masters, treat your slaves in the same way. Do not threaten them, since you know that he who is both their Master and yours is in heaven, and there is no favoritism with him." (Ephesians 6:8)
”Masters, treat your slaves justly and fairly, for you know that you also have a Master in heaven.” (Col. 1:4)
You can ignore those scriptures all you want. However, those mild criticisms made by Paul are not condemnatory against the institution of slavery of humans, whether they sold themselves into slavery or were captured prisoners.
Don’t make the mistake of confusing the term “slave of the Lord” for being an actual slave. Even a casual reader would quickly understand those phrases mean completely different things.