Introduction.
This letter is primarily addressed to ‘Philemon, our beloved and fellow worker', in whose house a portion of the Colossian church met for worship. Whilst three persons are mentioned in the greeting the later use of the singular ‘thou' (indicated in the commentary by an (S)), and the describing of him as ‘my brother', demonstrates that it is mainly addressed to one person. And with Paul emphasis is always on the first named. Thus to suggest that it was addressed to Archippus is as likely as a suggestion that the letter was written by Timothy because he is named alongside Paul.
Paul's central purpose is to restore to Philemon a runaway slave of Philemon's who had absconded with his master's goods. His name was Onesimus, and he had somehow met up with Paul in Rome where he was in hiding. Many escaped slaves made their way to Rome with a view to hiding out. It is very possible that Epaphras, who was from Colossae and was in Rome with Paul, had met him and was somehow the intermediary between the two, or it may be that he had sought Paul out because he felt that he could help him in his predicament. But all that can only be conjecture.
A secondary purpose, however, lies in Paul's hope that Philemon might then lend Onesimus back to him to minister to his needs in the Roman prison in which he lay, a ministry that he had already been fulfilling. It would be during Onesimus' loving ministrations that Paul would have learned the facts about his earlier life.
We must not underestimate what Paul was calling on both Onesimus and Philemon to do. A runaway slave, when found, was liable to the most extreme of punishment, even death by torture. So for Onesimus to go back on a voluntary basis because it was the right thing to do, with no absolute guarantee that he would not be severely punished and even branded, demonstrates Onesimus' genuine faith and dedication to Christ. Nothing else would have persuaded him to go back. And it demonstrates Paul's concern that there can be no half measures in Christian restitution. He could so easily have kept Onesimus by him and said nothing, knowing that, had Philemon been aware of it he would be only too glad to think that his slave could be of benefit to Paul. But Paul was not willing for one moment to compromise on what was absolutely right.
Nor must we overlook the seriousness of what Paul was requiring of Philemon. Philemon was a wealthy man in the upper classes, (demonstrated by the size of his house), and men of that kind saw the punishment of slaves who absconded as a social duty. The Roman empire had vast numbers of slaves and recognised that they had to be kept in tight submission in order to preserve the peace of the empire. It would therefore be seen by his contemporaries as Philemon's duty to punish Onesimus severely.
But the teaching of Jesus Christ had brought a totally new dimension to the question, for while it was true that Paul did not openly condemn slavery, something that would have been a waste of time, and would have put in danger the lives and well-being of Christian slaves wherever his teaching went, and have brought opprobrium on Christianity, (and if implemented would have destroyed society), his teaching, and that of Jesus Christ Himself, was undermining it totally. Masters had to love their slaves, treating them as brothers (1 Timothy 6:2) and were not to threaten them (Ephesians 6:9). What was more, many a free man went to his church and found himself submitting to his own slave's ministry in the church, for many overseers in the church were also slaves. It was thus not a situation that could survive for ever. In the case of Onesimus Philemon was being called on by Paul to once again take Onesimus into his confidence, to receive him with love, and to treat him not as a slave but as a brother. Slavery could not in the end survive that.
Lessons from Philemon.
One primary lesson of Philemon is that of being absolutely scrupulous in things pertaining to God and morality. Although it would put Onesimus in danger, neither Paul nor Onesimus were willing to compromise for one second on what they saw as right, no doubt after much prayer, even though it was at a great cost to them both. A second lesson arises out of Paul's plea to Philemon. It is that we show compassion and mercy towards those who truly repent. No greater offence could have been committed against Philemon than Onesimus had committed, but Philemon was being called on to forgive totally. A third lesson is that, like Paul, we should be loving and tactful, and not overbearing, when we seek to persuade someone to do something. Paul is here a model of tactfulness.