The first exchange of the imprisoned Paul for the returning Onesimus has to do with their common status as partners (koinonoi) within the faith community (koinonia; see commentary on v. 6) to which Philemon also belongs. As a theological abstraction and spiritual reality, this substitution is perhaps not terribly difficult to swallow. Onesimus's recent conversion to Christianity did result in a new parity with both Paul and Philemon. They are all believers; they all share the very same promises and convictions; they are partners, some more senior than others, in the same religious "firm."
Yet Paul demands that Philemon welcome Onesimus as though he were Philemon's apostle and patron. The verb translated "welcome" (proslambano) suggests the personal reception of one into another's home—a hospitable "homecoming" (Harris 1991:272). There is nothing abstract about this substitution, since it presumes an actual encounter between two persons. Onesimus is a crisis that Philemon cannot avoid; his conversion cannot be acknowledged from afar. Philemon must deal with Onesimus in person, first recognizing and honoring him as Paul's substitute, but then welcoming him as though he were a spiritual partner like Paul within the very household he once served as a slave.
Paul's challenging request serves a practical end. He realizes that religious conversions, such as those experienced by both Philemon and Onesimus, have very public results; they are not events that just happen to one and are then privatized and compartmentalized so they do not intrude on one's other activities. Conversion joins the believer with Christ in the cosmic salvation of God, whose grace transforms every aspect of human life. Philemon and Onesimus both must realize, as we all must, that in the crisis of a difficult reunion, we are sometimes forced to admit that how we relate to one another has changed with the changes that have taken place in us. For example, the changes that have taken place in our son, who is away from home at college, and in us, who experience a home without him, have changed forever the way we talk to and think about each other.
The previous arrangement between Onesimus and Philemon as slave and owner has been changed by their experience of grace. They are now partners (koinonoi) in a koinonia, where they share a new capacity to love one another as never before. The result of granting Paul's request is envisaged by the coupling of the words partner and welcome in characterizing the homecoming of Onesimus: he will be included as a member of the congregation, the equal of everyone in the house he once served as slave. Philemon is no longer his lord but a brother; they are partnered together with the Lord Jesus for their mutual salvation.
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