Whenever a person justifies killing by saying that it is god's will, whatever religion that person holds to contributes to bloodshed.
At least, that was my thought when posting.
Your question leads me to consider what would happen if the religion explicitly,consistently and completely forbid killing under any circumstance.
Would the man not kill?
Far more likely is that he'd find another way to justify it, a consideration that lends considerable weight to your argument.
Edit: I think I'd like to modify my statement. There is always the consideration of how rigidly a man holds to his religion, and more importantly his conscience. This post was written with those in mind whose religious practice is limited to a visit to church on sunday, and who fill the weeks in between with all manner of filth.
