Paul describes Onesimus as a spiritual asset and requests Philemon treat him as a partner as he would Paul. Paul even models this partnership by offering repayment of the debt Onesimus owed.
Paul didn't serve alone. A team of six exemplary men surrounded him. These brothers, like Paul, cared for the Colossians and sent their warm greetings.
Paul wraps up his letter with commendations, greetings, and final words. The first of these is found here: a warm introduction to two faithful brothers.