Vengeance belongs to God?

I opened to Romans 12. The following was the message I got: "Vengeance is mine; I will repay, saith the Lord.”:

The moment we entertain a desire to see another harmed for the wrong they have done, whether it be an ex-friend, a perennial enemy, a blatantly immoral politician, etc., we step outside the protection of Principle - we open ourselves to harm. If people spent as much time and effort watching against this as they do "unhealthy" food, society would be much healthier physically and morally!!

When the Bible declares: "Vengeance is mine; I will repay, saith the Lord.”  it is Love speaking, reassuring us that God is just, and far more qualified to right a wrong than we are. "The design of Love is to reform the sinner." (S&H)

In a litiguous society, it is a dangerous practice to sue for recompense for a wrong done, because it tends to absorb thought into unhealthy channels. An unselfed motive that sues with the purpose of protecting society of an abusive person or business brings with it the protection of Principle. 

If you have five minutes, I highly recommend this excerpt from the superb article "Love Your Enemies" by Mary Baker Eddy. It elucidates this subject far more completely than I have.