Peter reminds us of just how great and wonderful is the salvation we have in Christ (1Peter 1:1-12), and of the great responsibility we have to live holy lives before the holy God Who called us (1:13-2:10). Our conduct must be holy before our holy God (1:15), and honorable before the unbelieving world (2:11-3:12). After identifying and exhorting various groups to live holy and honorable lives (citizens, slaves, wives, husbands), Peter ends this section of his epistle by addressing all believers (3:8).
He writes, “Finally, all of you be of one mind, having compassion for one another; love as brothers, be tenderhearted, be courteous.” These actions or attitudes seem to be directed toward other believers in the church, but if so Peter quickly returns to the God-commended response to unbelievers who may treat us unjustly (3:9, cp. 2:19-23). “Not returning reviling for reviling” was the example Christ set for us (2:23), and which is now explicitly commanded (3:9). We are not to return evil for evil, but on the contrary blessing. Peter may have remembered the teaching of Jesus when He said, “But I say to you, love your enemies, bless those who curse you, do good to those who hate you, and pray for those who spitefully use you and persecute you” (Matthew 5:44). Part of our Christian calling is to bless people when they revile or mistreat us. And it is those who return blessing for evil who will inherit the blessing of the Lord!