I don't remember the exact number, but the suicide rate among people with functional types of autism, like aspergers, is way higher than the average person. I don't know about the religious aspect, but I'm sure it's the same or marginally lower, since religion shames you into staying alive against your will. there's also the community aspect of religion that helps a lot of people, however, if you have low social skills the it may still be challenging.
people with autism can still live very fulfilling lives, usually without any help. but if you didn't learn the social abilities then you can get a good therapist who can help you acquire them, even later in life.