Tomorrow one of the lessons in church  is the letter to Philemon.  Paul is easing the way for  the return of a runaway slave and Philemon is his master.  Paul is essence stands in for Christ, or models Christ or however we want to say it – He represents Christ in this letter in and amazing way.  He wants Onesimus, whose name means “useful” to be forgiven so he can be useful to Philemon and for Paul.

Luther in the opening of the commentary he wrote on Philemon says –

What Christ has done for us with God the Father, that St. Paul does also for
Onesimus with Philemon. For Christ emptied himself of his rights [Phil. 2:7] and
overcame the Father with love and humility, so that the Father had to put away his
wrath and rights, and receive us into favor for the sake of Christ, who so earnestly
advocates our cause and so heartily takes our part. For we are all his Onesimus[es]
if we believe.  LW 35;390