The bible is pro-slavery, by the way.
(A few citations) :
Exodus Chapter 21, verse 20:
If a man beats his male or female slave with a rod and the slave dies as a direct result, he must be punished, but he is not to be punished if the slave gets up after a day or two, since the slave is his property.
This verse treats human slaves as property. That's a bit of pro-slavery for you.
Your male and female slaves are to come from the nations around you; from them you may buy slaves. You may also buy some of the temporary residents living among you and members of their clans born in your country, and they will become your property. You can will them to your children as inherited and can make them slaves for life.
Need any more citations?