Paul reminds the Christians in Rome that their behaviour towards people in general matters a great deal. It is inevitable that in a fallen world we are going to come across numerous examples of evil, some of which have nothing to do with us being Christians. I suspect the evil here is different from the evil of persecution that Paul mentions earlier. There are lots of examples that can happen. A neighbour tells lies about you or suggests that your motives in something are not above board. The person in the shop keeps some of your change and denies it when you go back to ask about it. The workman you hired does not turn up and then you spot him working at someone else’s house. How should a Christian respond to wrong behaviour that does not have anything to do with him being a Christian?
Paul gives five details in his answer. First, we are not to retaliate in kind. In other words, we practice what Jesus taught: ‘You have heard that it was said, “An eye for an eye and a tooth for a tooth.” But I say to you, Do not resist the one who is evil. But if anyone slaps you on the right cheek, turn to him the other also. And if anyone would sue you and take your tunic, let him have your cloak as well. And if anyone forces you to go one mile, go with him two miles’ (Matt. 5:38-41).
Second, we have to know how to respond, and the way to discover this is to think about it beforehand, long before the evil action takes place. What Paul is indicating here is that a Christian should be determined to always live in a manner that will bring commendation. He does not do it to earn commendation, but he resolves to behave righteously. A Christian should never be known for anything that is underhand or dubious.
Third, every Christian is to be a peacemaker. What kind of people would Paul have in mind by ‘all’? Who would have lived in Rome at that time? Every kind of person. Paul is not suggesting that Christians tolerate evil or that they lower the standards that God has laid out. Yet we need to be wise as serpents and harmless as doves. Every neighbour, whatever his behaviour or religion, should be able to say about a Christian, ‘He or she loves peace.’
Fourth, a Christian should not take the law into his own hands. Instead, if he has been wronged, he leaves it for God to deal with. And God will deal with it. There are some things that belong to God and one of them is the authority to take vengeance. How does the Lord take vengeance? He will do so in providence in this life and in the punishments of a lost eternity in the next life.
His people, however, administer a particular form of punishment, which is to show kindness to the person who has affected them adversely. Putting burning coals on someone’s head is obviously a form of punishment. How does acts of kindness become a form of punishment? Because people have a conscience and they will be troubled at hurting people who are kind. They will sense that they are guilty of wrong behaviour. A biblical example of this is David and his responses to the wrong behaviour of Saul as he tried to demean and kill his replacement as king.