He might have been troubled: such a worthless man, how can I receive him? Besides, he fled and carried off this or that, if he did carry anything off. What hope is there for him? The Apostle knew that such anxious thoughts would arise. He did not want Philemon’s good deed to be performed with heaviness, as under a yoke. Rather, he wished it to be done willingly and with a peaceful disposition. Therefore he hastens to dispel such thoughts.
Since the most troubling of these thoughts is that Onesimus had proved useless, Saint Paul first and chiefly dwells on this. He speaks as if saying: it may occur to you, “Receive such a useless man?” I do not deny that he was useless. But he was, and is not. Now, after receiving the grace of regeneration, he has resolved to reject all evil and live soberly, righteously, and piously. He no longer thinks of anything useless, but only of “whatever is true, whatever is honorable, whatever is just, whatever is pure, whatever is lovely, whatever is commendable, if there is any virtue and if there is any praise” (Phil 4:8).
Such a man can no longer be regarded as useless, nor should one fear anything evil from him again. On the contrary, one must not lose him, but use his good services, for which he is now readier and more fit than before. Saint Paul wished to produce such thoughts in Philemon’s mind by calling Onesimus useful both to him and to himself.
Saint Chrysostom says: “See with what prudence he confesses the slave’s sin, and thereby calms the master’s anger. I know, he says, that he was useless. ‘But now he is useful to thee and to me.’ He did not say, ‘Now he will be useful,’ but, ‘He already is such,’ and not only to thee, but also to me.” “He has become pious and holy, and therefore useful to us both” (Theophylact).
The Apostle added his own person so that hope in the servant would be more credible. For if he is useful to Paul, who requires great correctness in everything, then all the more is he useful to his master.
“Whom I have sent back to thee.” If the Apostle had kept Onesimus with himself, the preceding praise would not have put Philemon at rest. He might have thought: he appears so there with you, but perhaps he does not even want to know me. The Apostle forestalls such a thought by sending Onesimus back, thereby saying to him: here, see for yourself what he is like.
Saint Chrysostom says: “By this also he calms the master’s anger, since he returns his slave to him. Masters are especially angry when others intercede with them for absent slaves. By this very thing he calmed Philemon still more.” He speaks as if saying: I have caught your fugitive, but I send him back to you not bound hand and foot. He himself, on his own feet, will come freely to you.
Onesimus, for his part, by presenting himself to the master before whom he was guilty, thereby showed full trust in his goodness and disposed him in his favor. In the course of this matter he greatly resembled the prodigal returning to his father. If this came to Philemon’s mind, as it could hardly fail to do, it could greatly dispose him, in receiving the runaway slave, to become an imitator of the way the father received the prodigal son.