Recompense to no man evil for evil. Provide things honest in the sight of all men.
Note 11 at Ro 12:17: There is an unwritten but widely understood code in human relations that says we should treat people the way they treat us. Jesus taught just the opposite (see note 1 at Lu 23:34), and Paul was reaffirming that same teaching here. If we are to be Christ-like, then we cannot give people what they deserve.
Note 12 at Ro 12:17: It is not enough just to be honest in the sight of God. This scripture commands us to also have integrity in the sight of man. This corresponds to "abstain from all appearance of evil" (1Th 5:22). We not only need to be right, but we also need to appear right as much as possible.