So those christian murders didn't feel justified? The same as extreme muslims feel justified? The only difference is the degree.
I don't know if the handful of people in American history who have murdered abortion providers in the name of religion thought they were justified.
What is the degree of difference between a person who murders a doctor and a person who blows up an innocent person in a bombing?
The difference is degree and belief, because parts of Islam teaches people to murder. Christians do not. .
For example, do you recall the father in Texas who murdered his daughters? A so-called "honor killing"? I don't think they ever caught the father? I was listening to a discussion on the radio about him a while back and someone who studies Islam said that fellow Muslims and mosques will hide the father for as long as it takes to protect him.