The book of Philemon is really small. So small in fact that you can't help but read it in one sitting. And it's a different book of the Bible because it reads more like a personal letter than the other books of the Bible do (well at least is does to me).
But the message of Philemon is very important. You've got a slave named Onesimus whose name literally means useful. But this guy hadn't been too useful to Philemon. In fact he took off and deserted him. The circumstances around his running away isn't clear. But what is clear is that Onesimus has had a change of heart. He's come to know Christ and he wants to do the right thing and go back to Philemon.
So Paul writes Philemon and asks him to take Onesimus back. Not just as a slave, but as a brother in Christ. Now no where in this letter do we know what happened after Philemon received Paul's letter. We don't know how he responded or if he took Onesimus back. But what we do know is what's expected of us in similar situations.
I don't know what your life is like, but right now I've got a 'Onesimus' in my life. Someone who messed up royally. Has done hurtful things. And doesn't have the greatest track record. But now they are looking to come back.
That leaves me in a dilemma. Do I choose to forgive and trust, knowing I could very well be hurt again? Or do I put an arms length distance between myself and this person?
If Paul's letter to Philemon is any indication, I've got no choice but to accept this person back as who they are- my sibling in the Lord. And how could I not? Because chances are one day I'll be knocking on someone else's door, needing grace extended back to me. And when that happens I can only hope that the person on the other end has the same grace and love as Paul had for Onesimus. The same grace and love that Christ has for me. And the same grace and love that I need to have for everyone who I cross paths with, deserters or not.