Having said that let us look at the letter to Philemon in which Paul pleads for Onesimus, Philemon’s slave. A slave who ran away from their masters had two options: a). Flight to a god’s temple; b). Flight to an owner’s friend. In this case Paul was the friend of the owner.
We ask the question:
"What is the Christian principle in demanding the slave’s freedom?
Pay attention to vs 8–9; 10,12; 22;
Vs 15–16 - the most important;
Vs 14 - Philemon should willingly free Onesimus.
“Christian owner of a Christian slave” = how could it be possible? Paul wants Philemon to realize that slavery among Christians is incompatible with being a Christian.
Why does Paul want to see Onesimus free? Why does he not say: “Philemon, treat your slave justly and fairly, stop threatening him, for you also have a master in heaven, and with him there is no partiality” (see Col 4:1=Eph 6:9)
A Christian master owning a Christian slave. Doesn’t it sound strange? How can they be equal in Christ, but unequal in society?
How can they be equal and unequal at the same time? How could they be equal spiritually, internally, in the assembly, but unequal physically, externally, in the world?
Both are Christians, and they must be equal “both in the flesh and in the Lord” (16).