Well, of course, we would be quick to point out that those abortion clinic bombers and those who murder abortionists in the name of Jesus aren't really Christians. The "faithful" Muslim could just as easily say the same thing about the Muslim terrorists.
It may be that in modern times Christians are relatively peaceful, but that is a mostly recent development. Whether it was the crusades to "liberate" the Holy Land from muslim control, or the Inquisition to smoke out heretics, or the brutal persecution of fellow Christians who had somewhat different theologies than the dominant one, Christian zeal has produced barbarism after barbarism in the record of history.
Now, I do believe that modern Christianity has turned into a very peaceful and good force in society, but that clearly was not always the case. And to single out Islam as a violent religion is unfair and hypocritical, in my view. What's more likely responsible for Islam's violent tendencies is the fact that most muslim countries are still trapped in the middle ages. When they finally enter modernity, they will likely abandon this self-destructive philosophy.
Fred Phelps, meet smith288.