I think neals meant "modern" Christianity, as in what has become of Christianity thanks to the age of reason. This excludes some Western (especially US) branches of Christianity.

Christianity was pacifist from the beginning. Jesus was all about non-violence:

“You have heard that it was said, ‘An eye for an eye and a tooth for a tooth.’ 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. - Matthew 5:38-39 ESV

I'm not sure why you're being downvoted. This was also my understanding. I highly recommend Mark Kurlansky's Nonviolence: History of a Dangerous Idea, which discusses non-violence in the history of early Christianity:

http://www.amazon.com/Nonviolence-History-Dangerous-Mark-Kur...

That is a little bit different, at least they are pissed or what they consider murders of human beings whereas these terrorists were pissed over writings.

Violent acts against those who disagree with you is not a Christian principal and goes directly against the teaching of our faith. Period. Anyone who supports or performs acts of violence as you are referencing are sinning and blaspheming when using a reference to God for their actions. No excuses, those are evil acts.

Hmmm, that's interesting. I got downvoted for saying that violent acts on abortion clinics are evil and go against a religious principal? Would the downvoter care to actually engage in a conversation about why they thought I an deemed worthy of a downvote? Is it because I identified myself with a religious belief? Please, please do engage with me.