Brothers and Sisters,
It can take a log time for the truth of the Gospel to be fully understood even by Christians. In the book of Philemon we see a complete dismantling of the rational for the evil of slavery, but it took close to two thousand years to get rid of slavery completely in the heart of humanity.
12 I am sending him—who is my very heart—back to you. 13 I would have liked to keep him with me so that he could take your place in helping me while I am in chains for the gospel. 14 But I did not want to do anything without your consent, so that any favor you do would not seem forced but would be voluntary. 15 Perhaps the reason he was separated from you for a little while was that you might have him back forever— 16 no longer as a slave, but better than a slave, as a dear brother. He is very dear to me but even dearer to you, both as a fellow man and as a brother in the Lord. (Philemon)
Please read Titus 2 - Philemon .
May the Lord richly bless you!