I sadly do not recall where I heard this but I'm amazed sometimes that I can have heard something like "An eye for an eye and a tooth for a tooth" so many times and a thought never occur to me. For some background, I was raised in the church and have read the Bible many times over my life. I usually read it each year so I'm very familiar with the text.
When we read "An eye for an eye and a tooth for a tooth" in Exodus we often think of how terrible this sounds. But, in reality the principle here is that a just penalty should be in equal measure to the damage caused. In practice what we often see is escalation, not equality in response. Its incredibly destructive.
Jesus in the sermon on the mount said,
“You have heard that it was said, ‘An eye for an eye and a tooth for a tooth.’ 39 But I say to you, Do not resist the one who is evil. But if anyone slaps you on the right cheek, turn to him the other also. 40 And if anyone would sue you and take your tunic, let him have your cloak as well. 41 And if anyone forces you to go one mile, go with him two miles. 42 Give to the one who begs from you, and do not refuse the one who would borrow from you.
43 “You have heard that it was said, ‘You shall love your neighbor and hate your enemy.’ 44 But I say to you, Love your enemies and pray for those who persecute you, 45 so that you may be sons of your Father who is in heaven. For he makes his sun rise on the evil and on the good, and sends rain on the just and on the unjust. 46 For if you love those who love you, what reward do you have? Do not even the tax collectors do the same? 47 And if you greet only your brothers, what more are you doing than others? Do not even the Gentiles do the same? 48 You therefore must be perfect, as your heavenly Father is perfect.
~ Matthew 5:38-48
There is something powerful in understanding the original intent and what Jesus adds. These days it seems many Christians have forgotten this teaching and the results. The results were that Europe was converted to Christianity. There is incredible power in loving your enemies. And not returning evil with evil. @k00b's post prompted me to write this.
Edit:
The other thing that prompted this is watching how people in the church are allowing politics to fuel their behavior in destructive ways. As Christians we should realize that politics is not the answer. Its Jesus.