Rather than taking revenge, the Christian is not to resist an evil person. Christ gives this concrete example in which someone is being sued for his coat.
There are Christians who will get deeply upset and deeply hurt by injustices and unreasonable things done to them in their place of employment merely because they are Christians. Well, you are bound to feel pain, but they allow it to gnaw away inside them, and they never forget it, and they become desperately unhappy in that place. Yes, but it would have been easier perhaps to absorb it, to bear it, and to pray to maintain our testimony. And that is a practical aspect of these instructions. In doing this we are only imitating God who faces the unreasonable behaviour of sinners rebelling in his world every day and yet continues to supply them with those good things that are necessary for life.