For rulers are not a terror to good works, but to the evil. Will you then not be afraid of the power? do that which is good, and you shall have praise of the same:
Read Chapter 13
Ambrosiaster
AD 400
Rulers here are kings who are created in order to correct behavior and prevent bad things from happening. They have the image of God, because everyone else is under one head. Commentary on Paul’s Epistles.
This can upset some people, when they think that Christians have often suffered persecution by these authorities. They say: “Were these Christians not doing good, since not only did the authorities not praise them, they punished and killed them!” The apostle’s words must be carefully considered. He does not say: “Do what is good and the authorities will praise you,” but: “Do what is good and you will have praise from him.” Whether someone in authority approves what you do or persecutes you, “you will have praise from him,” either when you win it by your obedience to God or when you earn your crown by persecution.