“Therefore, although in Christ I
could be bold and order you to do
what you ought to do, yet I prefer to
appeal to you on the basis of love.”

This is who was writing the letter

Paul could have told him what to do but instead he appealed to him on this basis

“Be kind and compassionate to one another, forgiving each other, just as in Christ
God forgave you”

This is who the letter was about

This when Onesimus became Paul's son

“Carry each other’s burdens, and in this way you will fulfill the law of
Christ”

This is who the letter was written to

This is what Paul said to do if Onesimus had done any wrong or owes him anything