Basically for Protestants in particular you have to have suicide be a hellworthy offense. Because if the only single thing you need to do to get into heaven is to accept Jesus as your lord and savior, requiring nothing else and wiping away any past wrongs, then there is no incentive not to just immediately kill yourself afterwards and go straight to heaven. It would quickly devolve into a death cult. Don't want that cuz you can't grift them all out of money if they kill themselves.