Do not avenge yourselves, beloved, but leave room for God’s wrath. For it is written: “Vengeance is Mine; I will repay, says the Lord.”
Paul moves vengeance off the believer’s shoulders by citing God’s own declaration: repayment belongs to the Lord, not to the offended.
This verse gives the theological reason the believer can lay down the weapon of self-avenging.
14Bless those who persecute you. Bless and do not curse. 15Rejoice with those who rejoice; weep with those who weep. 16Live in harmony with one another. Do not be proud, but associate with the lowly. Do not be conceited. 17Do not repay anyone evil for evil. Carefully consider what is right in the eyes of everybody. 18If it is possible on your part, live at peace with everyone. 19Do not avenge yourselves, beloved, but leave room for God’s wrath. For it is written: “Vengeance is Mine; I will repay, says the Lord.” 20On the contrary, 21Do not be overcome by evil, but overcome evil with good.