The main body of any letter from Paul deals more specifically with the crisis at hand. In this case the crisis is neither doctrinal nor a confused morality; Paul does not write to correct Philemon or members of his congregation. Certainly, getting the ideas of Christian faith straight is always Paul's concern and therefore always at least implicit in his writings. In making his appeal to Philemon in this letter, however, Paul is mainly interested in getting relationships straight. For him, the essential fruit of the "word of truth" is transformed relationships--a point clearly and decisively developed in his letter to the Colossians.
To understand the full gospel is to be guided and empowered toward newness of life with and for other persons. Because such changes in our relationships demonstrate devotion to the transcendent Lord God, they are often at odds with the surrounding secular order. The social conflict that emerges from being the church in an anti-God world stems from the revising and reforming of relationships. It is on the border between these two conflicting worlds that Paul finds Philemon.
Paul's request is that Philemon provide more concrete evidence--adding to the faith and love already given (vv. 4-7)--that God has indeed "rescued him from the dominion of darkness and brought him into the kingdom of the Son God loves" (see commentary on Col 1:13-14). On the surface, the problem has to do with Onesimus's status as a slave and believer. However, on closer reading the real crisis proves to have more to do with Philemon's status before God than with Onesimus's status before Philemon. Philemon's exemplary status within the church is being tested by the decision he must make with respect to Onesimus. The real purpose of Paul's letter is to convince Philemon to make a radical choice of splanchna that will help to mark out his congregation as one where the koinonia of faith is found. In this light, then, Paul's request intends two results: it intends a change in Onesimus's social status, presumably through his manumission, and it intends a change in Philemon's spiritual status, presumably through his reconciliation with Onesimus as a brother and partner in the faith.
Many recent scholars have called attention to Paul's rhetorical skill in crafting his appeal to Philemon. Literary analysis of Paul's letter reveals a conventional threefold pattern of "deliberative request," common in the ancient world, which seeks to persuade another to a different point of view while maintaining the integrity of both parties concerned.
The first part of such a writing, the "exordium," prepares the reader to hear a request by establishing a conducive atmosphere--of friendship, for instance, or worship (as in Heb 1:1-4). We may view Paul's epistolary prayers of thanksgiving and petition (vv. 4-7) as already functioning in this way. But if we want to study the main body of this letter as deliberative request, we need to understand that by setting aside his apostolic authority for the sake of his love for Philemon (vv. 8-9), Paul allows his audience to make a choice that is not coerced but will be issued with charity and integrity.
The second part of the request offers proof that the writer has the reader's (in this case Philemon's) best interests at heart. Thus Paul makes his appeal for Onesimus only after establishing that his relationship with Philemon is neither controlling nor coercive (v. 10). Paul's appeal is backed up by a series of reasons that a favorable decision for Onesimus would actually be to Philemon's advantage, enhancing his reputation as a Christian leader (vv. 11-16).
The final part of deliberative rhetoric is the "peroration," in which the author repeats his appeal but posits it on a more personal basis (vv. 17-22).