True but it is just another reason that they could
And peoe who believe that please don't take offence, I don't expect you to go and commit atrocities for it but people can use that as an excuse
I was confused for a second and thought you were referring to all the atrocities committed explicitly in the name of Christianity. Which were logical, merciful acts, under Christian doctrine. The most merciful act is to convert as many people as possible, even if you have to kill half of them first. The only reason Christianity as a doctrine co-exists at all nowadays is because it lacks the military support it used to rely on.
Maybe the right religion can scare a murderer out of doing murders. I don't see how, though. Christianity teaches that we're all sinners, and none of us can reach heaven unless we become followers of Jesus. (Because Jesus takes your sin... but only if you join the club). There's no real reason to stop murdering, you're already "evil" and you already get to go to heaven anyway.
Plus you're expected to rely on faith rather than society (which is supposedly evil just like you). Reject society, listen to mysterious compulsions, and as long as you're faithful you're definitely going to heaven... Good recipe for a serial killer, particularly if the person's already sick.
Sure, Christianity points out that murder is bad. It's right up there with respecting the Sabbath (whether it's Saturday or Sunday). Some of them are outright impossible: Don't "covet" your neighbor's house or wife? How?? (Also, I guess coveting your neighbor's livestock, money, car, or husband is just fine).
Even "Thou shalt not kill" is ridiculous. Apparently it's a mistranslation and ought to be "murder"... Yet people faithfully keep using the word "kill" as if it makes any sense.
The ten commandments have three rules which every culture already has: Don't kill without reason, don't steal things, and don't say people did crimes when they didn't. Cultures don't survive without those rules, even small isolated ones. Then it mixes those with 7 ancient Israeli values which basically don't apply at all to anyone else. Except adultery, maybe, though adultery can mean a lot of different things and isn't really important. Where is "Thou shall not rape?" I guess God hadn't invented that value yet, or didn't think the desert tribes were ready for women to own their own bodies.
Anyway, Christians take God's name in vain all the time, and adulter, and covet, and steal, so I don't see how faith is stopping them from murdering if they actually wanted to.
Meanwhile, rational people see that committing atrocities is high risk for generally little or no gain. So they don't.