Does the Bible support slavery?
Not at all. Slavery is an institution created by man.
In fact the Bible tells us that we are all God's offspring (Acts 17:29) and He has made from one blood all the nations of men, to live in this world (Acts 17:26).
Though many ancient kingdoms and empires practiced slavery, Israel was always reminded by God of its slavery in Egypt (Deuteronomy 5:15) and was required to release its bondservants. The Old Testament Law demanded that all slaves should eventually be set free (Exodus 21:2, Leviticus 25:39-41).
The Roman Empire whom Paul was a subject practiced slavery and it was a matter of the law of the land, that prompted Paul to point towards certain facts of his time. This does not mean that Paul is approving of slavery. Ephesians 6:5-9 is not condoning slavery as many believe this scripture to be, but instructing servants to be good workers working cheerfully and faithfully to please God (Colossians 3:22-24).
Galatians 3:28 tells us that, "There is neither Jew nor Greek, there is neither bond nor free, there is neither male nor female: for ye are all one in Christ Jesus." This makes us all equal before God. We are God's creation, created in His image (Genesis 1:27).
Moreover, Jesus came to set captives free (John 8:36) and not to enslave or preach slavery.