Something similar (but maybe not quite as tragic) is why my wife and mother-in-law lost their religion. My MIL was catholic, and initially tried to raise my wife as such. But my wife was really painfully sick for years as a child. Basically all of her elementary school years were spent either in pain or unconscious. She doesn’t even remember most of her childhood. Watching her go through it and not being able to do anything to help was what caused my MIL (and by extension, my wife) to lose religion. Because what kind of benevolent god would intentionally inflict that on a child?