When a psycho becomes "religious" he doesn't get better, he gets worse. The belief in hell profits nothing to make him afraid of his words and acts; if he used to wish death to others, he's only going to become more like the devil, also wishing hell. If you're expecting to see someone coming to you with knives and guns, you won't identify most of them. Many are more classy than that, their weapon is inside their head. Thus if you don't have one too you are very likely at risk of being left by them if not dead, completely wrecked, without they ever touching you with their hands.
If they read about sheep and goats, they'll certainly not humble themselves, they will decide who is who. If they read about predestination, they're going to despise the Source and choose the "destination", obviously "heaven" to themselves and "hell" to whoever steps on their toes.
Those people from XIX century's Boston had a reason to thank God for not having been born in XVI century's Geneva.
