Considered a genuine Pauline epistle, the letter to Philemon is dated around 54-55 AD and was written from an imprisonment (probably in Ephesus) that Paul expects will soon be over. 

This short letter addressed to three specific individuals concerns Onesimus, a slave from Colossae (Col 4:9), who had run away from his master, perhaps guilty of theft in the process (Phlm 18). Onesimus was converted to Christ by Paul (Phlm 10). Paul sends him back to his master (Phlm 12) with this letter asking that he be welcomed willingly by his old master (Phlm 8–10, 14, 17) not just as a slave but as a brother in Christ (Phlm 16). Paul uses very strong arguments (especially Phlm 19) in his touching appeal on behalf of Onesimus. It is unlikely that Paul is subtly hinting that he would like to retain Onesimus as his own slave, lent to Paul by his master. Rather, he suggests he would like to have Onesimus work with him for the gospel (Phlm 13, 20–21). There is, however, little evidence connecting this Onesimus with a bishop of Ephesus of the same name mentioned by Ignatius of Antioch (ca. A.D. 110).

Paul’s letter deals with an accepted institution of antiquity, human slavery. But Paul breathes into this letter the spirit of Christ and of equality within the Christian community. He does not attack slavery directly, for this is something the Christian communities of the first century were in no position to do, and the expectation that Christ would soon come again militated against social reforms. Yet Paul, by presenting Onesimus as “brother, beloved…to me, but even more so to you” (Phlm 16), voiced an idea revolutionary in that day and destined to break down worldly barriers of division “in the Lord.”