One of the people Paul chose to deliver the letters we know as Colossians and Ephesians was a man named Onesimus. Onesimus was originally from Colossae, and would have been known to the people there. But Paul was compelled to write a separate letter for him. This was because Onesimus had been the slave of a wealthy Colossian named Philemon, in whose home the church met. Onesimus had run away, probably robbing Philemon in the process. In Rome he had become a follower of Jesus. He’d been helping Paul in prison, but now Paul needed him to return to Colossae. Paul’s hope was that Philemon would not only forgive Onesimus, but welcome him as a brother and no longer a slave.
Paul’s brief letter to Philemon stresses the change in Onesimus’s life. His name meant useful in Greek, and Paul tells Philemon that while he had formerly been useless (a servant Philemon couldn’t count on), now he could be useful to both of them. Paul doesn’t put Philemon under any obligation. His appeal is on the basis of love, and he promises to honor the demands of justice by making restitution himself if necessary.
Most likely Paul’s appeal was successful, or this letter would not have been preserved. In the life of Onesimus we have a clear example of the kind of transformation that occurred in thousands of lives as the gospel message spread throughout the Roman Empire.