(O·nesʹi·mus) [Profitable].

A runaway slave whom Paul helped to become a Christian. Onesimus had been a servant of Philemon, a Colossian Christian, but had run away from Colossae to Rome. He may even have first robbed his master in order to make the journey. (Col 4:9; Phm 18) It is quite possible that he had met or at least heard of Paul through Philemon; for, though no visit of Paul to Colossae on the missionary tours is specifically mentioned, Paul did travel through the general area and was acquainted with Philemon. (Ac 18:22, 23; Phm 5, 19, 22) At any rate, in some unstated way, Onesimus became associated with Paul in Rome, and he soon became a Christian. (Phm 10) In great contrast with his former uselessness to Philemon as a slave, he now became most useful to Paul as a minister, a “faithful and beloved brother” whom Paul calls “my own tender affections.”​—Col 4:9; Phm 11, 12.

Nonetheless, Onesimus was still a runaway slave, and the social order of the day obliged Paul to send him back to his owner, though with  reluctance in view of how good a companion he had become. The apostle, however, had no way of forcing Onesimus to make the return, so it depended on and resulted from Onesimus’ own willingness to go. In dispatching Onesimus, Paul arranged for Tychicus to accompany him and for the two to carry a letter and a report to Colossae. (Col 4:7-9) Additionally, Paul gave Onesimus his letter to Philemon, even though it was late enough in his imprisonment that Paul was expecting release and looking forward to visiting Philemon personally. (Phm 22) This latter letter might be termed one of reintroduction and recommendation for Onesimus, in which Paul assured Philemon of the good Christian ministry and new personality of Onesimus, and in which he pleaded that the reunion be more like that of two Christians than that of a slave and his master. Paul asked that any outstanding debt that Onesimus owed Philemon be charged to the apostle’s account. (Phm 12-22) Incidentally, in the letter to the Colossians that Onesimus and Tychicus were carrying, Paul dealt with the Christian principles governing the relationship of slave and master.​—Col 3:22–4:1.