Perhaps the reason he [Onesimus] was separated from you for a little while was that you might have him back forever— 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 1:15–16
Notice that Paul speaks of Onesimus as “a fellow man” and “a brother in the Lord.” In this one sentence, any justification for slavery is destroyed. In a culture based on slave labor [Rome], the Holy Spirit inspires the Apostle to obliterate slavery. The mask is pulled off and Christians are to see that a slave is not a beast of burden but an equal with all people and can, if a believer in Jesus, be a full member in the Church.
With this new understanding, how could any Christian justify slavery? Many people went to great lengths to overlook this truth, but not all. Church history records that Onesimus was freed. And in letters from Ignatius to the church in Ephesus, Onesimus is referred to as the bishop of Ephesus.
So often, we forget what God has revealed to us. God’s Word teaches us how we are to live. And when our day comes: God “will repay each one according to his deeds.”