In the first half of this little letter, all that we explicitly know is that Paul is appealing. We are not told what Paul is appealing for, only how and for whom he is appealing. Instead of speaking as one with authority, that is, instead of speaking as an apostle of the Lord Jesus, Paul appeals as a prisoner of Christ Jesus.
In line with this, though Paul would have liked to have kept Onesimus, he is sending him back to Philemon so that Philemon can act freely. Parents should long for that time when law-like commands transition to Proverbs-like appeals. Obedience is the glory of children, but there is a kind of obedience that exasperates. “Bring me my glass son.” “Ok, which hand should I use? Where should I touch the glass? Do you want me to fill it up? How full?” When a child is older you can say “mow the lawn,” and walk away with confidence. While they’re younger, you have to stick around to direct and answer questions. Likewise, shepherds may speak more gently to mature sheep. They make appeals so that the sheep may act freely. A sheep that can be led with the slightest touch is a joy to the shepherd.
Shepherds shouldn’t coddle the sheep into immaturity. Sheep shouldn’t cultivate a Toys-R-Us attitude wherein they play the day away unless commanded to do something. Maturity in Christ means that not everything needs to be spelled out and that appeals come as powerfully as commands.