I think it’s important because it affects how we treat each other. If there is no free will, Heaven and Hell make no sense and nobody is “evil”. People like sociopaths who deliberately harm others for personal gain don’t deserve to be punished. They deserve empathy like everyone else, becase if we had their genetic make-up and their life experiences, we would be sociopaths too. I believe people who commit crimes should be helped rather than punished, and that’s partly because I don’t believe in free will.