By Stan Cox, on June 28th, 2011

The appropriate response of Philemon to Paul’s petition on behalf of the slave Onesimus would be to receive him back, and treat him as a brother in Christ. Paul encouraged him to receive him, “that is, my own heart” (12); and “as you would me” (17).
Further, Paul’s purpose was to have Philemon act out of good will rather than necessity. This is a common theme in scripture. God does not want his children to act appropriately merely out of necessity. He wants his children to do so out of a sense of right, and willingly.
Finally, Paul appealed to the possibility of divine providence in the actions of Onesimus. Paul didn’t deny that the slave was wrong in running away, but believed that God has used that as an opportunity for the man to be taught the truth: “perhaps he departed for a while for this purpose, that you might receive him forever” (15).
The relationship of Onesimus to Philemon had now changed. They were brothers in Christ. Such a relationship demands fraternal devotion and a recognition of common heritage and equality (cf. Galatians 3:28).
By Stan Cox, on October 31st, 2009

Philemon 1-7
At the beginning of Paul’s letter to Philemon, he was very complimentary of his friend and brother. He acknowledged the “love and faith” that he had toward “the Lord Jesus and toward all the saints.” He also mentioned the good things in Philemon’s character, and the fact that the brethren had been “refreshed” by his character and works.
His diplomacy had a very specific and important purpose. Paul desired that Philemon be receptive to his petition on behalf of Onesimus. By his kind words and solicitous manner, Paul influenced Philemon to do the right thing in accepting Onesimus back, not only as a slave, but as a “beloved brother” (vs. 16).
A distinction must be made. Paul was not “flattering” Philemon. Flattery is deceitful and insincere. Paul was honest and genuine in his praise of a worthy brother. Also, seeking to influence people to do right is very different from attempts to manipulate. It is different both in tactics and motivation. What Paul did in his praise of Philemon was good and right, and to be emulated by all Christians.
By Stan Cox, on May 6th, 2008

Philemon 8-11
In the eighth verse of his epistle to Philemon, Paul clearly reveals the purpose of his writing. Philemon’s slave, Onesimus, had apparently ran away from Philemon. He had met Paul, and Paul had converted him to Christ (vs 10). As Paul put it, “who once was unprofitable to you, but now is profitable to you and to me” (vs. 11).
While Paul had the authority to command Philemon in his treatment of the slave, he did not exercise that prerogative. Instead, he appealed to Philemon as a faithful and loving child of God.
Onesimus had broken the law in running away. His return could have been dangerous for him, but Paul was convinced that the love of Christ, present in Philemon, would moderate his response to Onesimus’ return — especially since Onesimus was now a brother in Christ.
No matter our relative positions in life, when we are Christians, we are brethren.