
Evil, by its nature has no limit. By putting into this world a worst thing god provides another mercy. A strange form of it. But for those who believe, now they know exactly how bad things can get. Instead of living in fear of the infinite depths of evil that *could* happen to them. Certainty, familiarity, and knowledge of a terrible worst thing can diminish all other bad things. So the idea of hell alone is another powerful and good idea.
I must not have done a good job at condensing all the religious literature I've read to you in a character limited response. I'm sorry. I'm not even a priest. Definitely not the right person and you are understandably frustrated. I'll do the best I can to answer any more questions though