If you really believe that Islam kills people then you must believe that Christianity does also. Because those KKK guys were good upstanding Christians.
You cannot have a rational discussion with anybody that believe a certain religion or race all behave the same. I don't know the equivalent word on the religious side. But on the race side it would be called racism.
The difference is, the bible itself does not condone killing infidels or others just because their different. Also, it doesnt reward you for killing those people in the name of God. Please find me a passage in the new testament for this.
However, the same can not be said for islam.