Most people avoid conflict. Therefore, most people don't insult people to their face, either provoked or unprovoked. So it is easy to read this verse and say, "I don't do that". However, the truth is we may not "pay evil" or "insult" directly to someone, but we are worse by doing it behind their back and to our "friends" so that they don't have a chance to respond.
Lord, help me to see when I fail so that I may be better, and help me to show grace and love when others show disrespect and anger.