Speaking as an ex-catholic, I can confidently say that the concept of hell was the single biggest black cloud over my otherwise happy childhood. It is also the single biggest reason that I still hold a grudge against the fuckheads who put the idea into children's heads in the first place.

Once I distilled away all the bullshit from the faith and found nothing left, it became patently obvious that the purpose of the concept of hell is to use fear as a weapon. The church found a way to get people to follow their improbable doctrines: just bump up the consequences of not following them, either through direct physical violence or the threat of violence in the hereafter. The more flimsy the evidence for the idea, the more you need to increase the threat to make it stick. Hence the concept of hell. (If you want a Dennett-style Darwinian explanation, those doctrines that didn't have the concept of hell tended to fade away, and those that had it tended to survive because the threat works on some people.)

Teaching the concept of hell to children is child abuse, pure and simple. In my case it ultimately backfired on the church, because it turned me from a passive atheist to an anti-theist who is actively opposed to religion because it does a lot harm. I don't spend a lot of time railing against religion, because I feel like defining my own projects instead of letting my enemies define my projects for me, and I've got better things to do. But thanks to their putting a damper on my childhood with the concept of hell, I'll now cheerfully cut religion to pieces whenever and wherever it crosses my path.