While I won't suggest this is society's distinction between the two, in my mind it's about what happens if you exert independent thought that conflicts with the

While I won't suggest this is society's distinction between the two, in my mind it's about what happens if you exert independent thought that conflicts with the institution's beliefs and what happens if you attempt to leave the group. Many ex-Mormons claim their former church is a cult and that life in Mormon dominated areas become very difficult for those who have left the faith. Same for Jehovah's Witness but the impact is smaller because not many areas are dominated by them and you don't have to move far to get away from it. On the other hand, the worst cults will hunt you down across the country (and possibly the Earth) if your existence is offensive enough to them, which isn't something typically seen when leaving a mainstream Christian religion. A Mormon in Alabama leaving the church isn't likely to face much social ostracism while a Southern Baptist might, especially if they reject Christianity entirely, but their life isn't likely to be in danger.