All of these examples deal with the attitude of one's heart in exhibiting patience and love, and Jesus' intent in them is to raise us above the righteousness of the Pharisees to the higher righteousness of God's calling.
In Jesus, we have the ultimate example in responding correctly, when He said, while hanging on the stake, "Father, forgive them, for they do not know what they do" (Luke 23:34). Not long thereafter, Stephen, when faced with death at the hands of a mob of hateful Jews, rather than responding with epithets or seeking revenge, beseeched, "Lord, do not charge them with this sin" (Acts 7:60). Both had a generous spirit and a true love for their fellow man.
Matthew 5:41 speaks of being pressed into service to do a task for another. It might be good to remember that each of us has been pressed into the service of Almighty God and asked to go the extra mile. For most of us, our calling was unlooked for and perhaps even came at an inopportune time in our lives. Yet, a Higher Authority has put us into service to do a work. Have we taken on our burden and cheerfully gone an extra mile for God?
And beyond God Himself, in our marriages, in raising our children, in dealing with each other, and in interacting with those outside our fellowship, we should be doing all we can to go that extra mile. By doing so, we reflect the higher standards of God's law, the standard of truly loving God and each other. This attitude will take us far beyond the righteousness of the scribes and Pharisees.