Supposing that God exists, would he punish disbelievers? John Quincy Adams says that a good God would not:
“Any human creature, who seeks the general welfare of the Society he belongs to, does all the good, and as little harm, as is possible, and adheres to what he has been taught from his Infancy to be his duty, can never be exposed to the resentment of a good and wise god, whatever the mode of his worship may be.”
(Source: JQA's personal diary entry of November 27, 1785, written when he was 18 years old)