As a business owner and an owner of slaves, Philemon’s financial success was dependent upon loyalty amongst his laborers. Restless slaves could prove costly. If even one escaped successfully, many might follow in his wake. When Paul asked Philemon to free Onesimus—and charge any wrong to Paul’s own account (v. 18)—he was asking Philemon to risk both the stability of his business and his reputation in Roman society. Paul urged Philemon to display justice toward Onesimus, justice in light of Christ’s work in the storyline of Scripture.
Principles of justice and mercy found in passages like Deut 19:15-21 and 25:1-4 shaped Paul’s injunction to Philemon. In Deut 19:15-21, Moses commanded that checks and balances needed to be followed so that an accused person would receive a fair trial. Judges needed to carefully investigate matters so that legal verdicts would be based upon fact. Moses wrote, “Life for life, eye for eye, tooth for tooth, hand for hand, and foot for foot” (Deut 19:21). The innocent were to be vindicated and the guilty were to be punished (Deut 25:1-2). As Israel maintained justice in their disputes, they would be recognized as God’s special people, far above the nations surrounding them (Deut 26:16-19).
Paul expressed the Mosaic principles for justly handling disputes by articulating them in light of Christ. For Paul, fairness rested not on just the circumstances of a case but upon God’s revelation of Himself in Christ and his own special role as the evangelist who spoke the gospel message to Philemon. Paul’s logic placed himself and Philemon as recipients of God’s great grace in Christ, and Philemon as a debtor to Paul in the gospel. Paul therefore asked Philemon to practice justice by demonstrating mercy to his former slave Onesimus and freeing him to minister with Paul (vv. 8-20). Paul wished for Philemon to deal with the former slave as he would the apostle himself (vv. 17-18), and to keep in mind that he owed Paul no small debt in the gospel as well (v. 19).