Philemon 15-19 For perhaps he therefore departed for a season, that thou shouldest receive him for ever; not now as a servant, but above a servant, a brother beloved, specially to me, but how much more unto thee, both in the flesh, and in the Lord? If thou count me therefore a partner, receive him as myself. If he hath wronged thee, or oweth thee ought, put that on mine account; I Paul have written it with mine own hand, I will repay it: albeit I do not say to thee how thou owest unto me even thine own self besides.
The fact that Onesimus departed for a season is interesting. First of all it is interesting that Paul uses these terms to describe a sin that Onesimus had committed against his master, by abandoning his responsibilities as a servant and fleeing from him. Secondly, Onesimus fled from a Christian master, in whose house worship services were held (Vs. 2). And thirdly, it appears that Onesimus' departure for a season held a providential message for Christians of all ages. One lesson is that God's arms of love are always open for those that depart into sin for a season, recognize their mistakes, and return to Him as their Master. Another lesson is, that true repentance, which leads one to become a Christian, will result in making amends to those that may have been harmed due to one's sinful past.
Philemon lost a servant for a season, but gained much more with his return, both in the flesh, and in the Lord. Undoubtedly Onesimus returned to Philemon as a much better servant than when he left. The service of a true Christian to another will never be slack or rendered half-heartedly. Whether in secular life or in spiritual service, a conscientious Christian will always give his or her best. But more than that, Onesimus returned to Philemon as a beloved brother in Christ. With their common affection for the same heavenly Father, what a great benefit Onesimus would be to Philemon, and to the church in thy house (Vs. 2).
On behalf of Onesimus, Paul appealed to Philemon as a partner - one having a common bond in service to Jesus Christ. A similar reference was made by Paul regarding Titus when he referred to him as my partner and fellow-helper in service to the church at Corinth (2 Cor. 8:23). Here in the lesson text, Paul requested that Philemon receive Onesimus as a brother, just as he received Paul. This same relationship existed between God, Jesus, and His apostles. Notice what Jesus told the twelve: He that receiveth you receiveth Me, and he that receiveth Me receiveth Him that sent Me (Matt. 10:40). Considering this, for Philemon to receive Paul as a friend and fellow-laborer in Christ, he must also receive Onesimus, Paul's convert to Christ.
If he hath wronged thee, or oweth thee ought, put that on mine account. Some contend that this verse tells us that Onesimus had stolen money or other valuable items from Philemon. However, by using the prefix "if," this seems to be a hypothetical statement by Paul. There is no doubt that Onesimus had wronged Philemon, by unfaithful service, and by fleeing from his household. However, it seems likely that this verse, and the one following, teaches a lesson on the forgiveness that is due to a truly repentant soul. Encouraged by Paul, Onesimus desired to return to his master, Philemon, and make amends for the sinful acts he committed. Paul's plea is that Philemon will, as a child of God, completely forgive Onesimus of any debt of wrongdoing, and accept him back as a servant and as a brother in Christ.
For any debt that may have been created, Paul tells Philemon to put that on mine account - that is, charge it to me. I Paul have written it with mine own hand, I will repay it. Here was Paul's written assurance - a commitment that if Onesimus owed anything to Philemon, he would repay it himself. With this promise to repay any debt being made, Paul immediately reminds Philemon of the debt he owes him. This debt was created when Philemon became a child of God through Paul's influential preaching of the gospel message of salvation in Christ Jesus. This is the same message taught by our Savior in the parable of the unmerciful servant (See Matt. 18:23-35). To be forgiven, one must likewise forgive others. In this insightful message, Paul beseeches Philemon to forgive his Servant Onesimus, and accept him back as Brother Onesimus - a fellow Christian. God cancels the debt of every repentant Christian, if they do the same for others!