Onesimus came to faith through the work of Paul. Joyfully he responds to God’s grace with works of service. He immediately offers to help Paul and starts running errands for him whilst he is in prison, probably another house arrest of some kind. How beautiful are the feet of those who bring the good news. He thinks to himself, what a privilege to support the ministry of God’s Word. Everything is going so well, life is good, but then the apostle tells him that he must go back to Colossae. Yes, he has become a Christian. He has been washed clean by the blood of Jesus, sins forgiven. But that does not excuse him from his responsibilities. Salvation has not removed him from this world. He is still a runaway slave. According to Roman law, he still belongs to Philemon and he must go back to his master. He cannot serve Paul unless he has been released or specifically sent to do so. If he truly comes to know Christ, then he must submit to him in this. Genuine repentance and faith must show itself in actions.

A return to your master would be a frightening prospect, but it is not all doom and gloom because Philemon is also a Christian. So there is hope, and what is more, Paul is also going to write a letter. He is going to do his best to remind Philemon of his Christian duty to forgive so that there can be peace between master and slave, and they can be reconciled (see 2 Corinthians 5:11–21).

Together with Tychicus, Onesimus makes the journey back to Colossae. Coming to the town, they make their way to the house of Philemon. There is a knock on Philemon's door. A surprise to see the runaway slave come back and then this letter from Paul. So if you consider me a partner, welcome him [Onesimus] as you would welcome me (Philemon 1:17).

Everything mentioned earlier in the letter builds up to this single request. I know that you love the Lord Jesus and his people (Philemon 1:5). I know that you have refreshed the hearts of many believers (Philemon 1:7). You are generous with your resources and kind in your heart. You have been reconciled to God through the blood of Christ. You know the grace and peace that comes from him. You know the undeserving love that he has shown to us (Philemon 1:9). He has loved us and chosen us in Christ before the foundation of the world. He died for us while we were still his enemies. He has removed our sin as far as the east is from the west. Act now in a manner that is consistent with the truth that you confess. Receive Onesimus as you would receive me. Be gracious to him. Forgive his debt, charge it to my account if you must (Philemon 1:18), but whatever it takes, be reconciled to him; he is your brother.

Here then is the impact that the good news of Jesus Christ ought to have on Christian believers. Reconciliation. Forgiven people must forgive. If we have hurt our brother so that he has something against us, we must take the steps to be reconciled to him. If someone who hurt us repents and asks for mercy, we must forgive them. We must let go of bitterness, resentment, and anger. We must receive them as Philemon would receive Paul.