SSSUUUUURRRREEEE it is! As long as there are no people of OTHER religious persuasians around. If there are, then the "religion of peace" becomes the "religion of pieces", as any non-Muslims are FORCED to either convert to Islam or be reduced to piles of quivering, dead, hamburger.
Muslims spend their time killing each other when there are no other religion's around to kill. Actually, they spend significant time killing each other even when there are other religions around (that they are also killing).