Yep - and even when Jesus quoted it from the old testament, he said it was wrong! Doesn't fit with an "inerrancy of the scriptures" model. (maybe a little off-topic? sorry! )
You have heard that it was said, 'An eye for an eye and a tooth for a tooth.' But I say to you, offer no resistance to one who is evil. When someone strikes you on (your) right cheek, turn the other one to him as well.
For if you love those who love you, what recompense will you have? Do not the tax collectors do the same?
Matthew 5 38-39, 46
Yes, too bad few Christians ever followed these words.
Per the Christian story, Jesus was executed anyway. His attitude and teachings changed nothing. All it did was put a Christian veneer on the same people and instead of being open and honest about their warring actions, they turned to hypocrisy.
See Dubya "I'm a Christian but believe in starting wars for no reason" Bush for an example.
If no one wanted to exert their power over others, were enlightened, respected the rights of others, etc. then wars and executions would indeed be unnecessary to protect those who follow this idea. Unfortunately, the world has people who have absolutely no respect for others and think nothing of abusing or killing them. Self defense or defense of a society from these sorts is not unreasonable - indeed, not defending yourself and society from such people is what is unreasonable.
Someone posted earlier that killing was bad, period.
I believe in self-defense. If you killed someone defending yourself or your family, is it still a bad thing for you to have done? Should you have turned the other cheek and let your abusers do whatever they want?