A few centuries after the death of Gautama Bussha, a Sri Lankan prince mounted a Buddhist relic on his spear and went on a crusade against his Hindu neighbors. And the Buddhist monasteries of Japan used to sort out their dogmatic disputed with private armies.

The moral of the story ?

It doesn't really matter what a faith teaches - sooner or later someone will kill in its name, and feel extremely pious and justified in doing so. And let's not even get started on the liberties that sooner or later get taken with interpretations for the sake of temporal expediency - the convoluted arguments the Church had to develop to resolve the glaringly obvious discrepancy between the ideals of the warrior class and its masters on one side and the pacifistic ideals of Christianity are a good example of that. Well, actually, it was rather older - regardless of what had once been taught, it became necessary for a Christian to be capable of being a soldier the second the Roman Empire went Christian and had to be defended against invading pagans...
Well, you get the idea. Nothing, but nothing, drags down the noblest of ideals like the practical necessities of an uncaring reality.