Generosity, Not Revenge

This is the most difficult passage in the Sermon on the Mount. What can it possibly mean to not resist the evil person? Based on Jesus' examples, as He gives them here, He meant that we are not to wrathfully resist, not to resist in our sinful flesh, but to resist evil only and always with good. Expose the thief's rapaciousness -- by your generosity, not by your own greed.