Hi MA, welcome aboard
I think your right about every faith having zealots but the Jehovas Witness zealots seldom come to the door with an AK-47.
The biggest difference seems to be most religious fanatics strive to bring you into the fold whereas the Islamic fanatics just want to kill you for not being in the fold already.
Now I'm sure I'm making an unfair blanket aspersion of Islamics but if a Purple Midget keeps hitting me in the name of Purple and the rest of the Purple Midgets say nothing then as far as I'm concerned all Purple Midgets are bad.