Philemon 1:6

that the fellowship of thy faith may become effectual, in the knowledge of every good thing which is in you, unto Christ.

The meaning of this verse is somewhat difficult to understand, but perhaps Hendriksen's paraphrase of it is adequate:

The more thoroughly Philemon recognizes how greatly he himself has been benefited, the more inclined will he be to extend mercy and pardon to others, especially to Onesimus. And the very fact that Philemon has manifested such a fine spirit in the past convinces the apostle that he is not writing in vain.[18]

Whether Hendriksen's view is completely accurate or not, one thing is certain. The name of Onesimus, not yet mentioned by Paul, is nevertheless in the background of all that Paul wrote in these verses. A part of the delicacy and charm of the epistle lies in the very hesitation on the part of Paul in bringing up what must have been considered to be a very unpleasant subject with his friend Philemon. Paul cleared the ground and cultivated the soil very carefully planting the name of Onesimus in Philemon 1:1:10.