Advanced considerations of hell tend to focus on regret, sorrow, and despair. Eternal sadness, rather than eternal physical punishment. The word-picture presented to me by my mother (a Roman Catholic, well-educated in theology, philosophy, and the sciences) was distasteful, but enlightening (I've embellished it a little):
Hell is like going to a party... the best party ever. You've been looking forward to it for so long, you've thought about nothing else for ages, and now it's here! Everyone will be there, everyone will be happy, and there will be every kind of fun thing to do.
But when you get there and step through the door, just as your heart is swelling up with so much happiness that you think you might just pop... you look down and realize that you are naked and covered in your own filth. Shit from head to toe, in your hair, your fingernails, between your teeth... everywhere!
Horrified, you can only think of getting away, hiding away where no one can see you while you clean up. So, you dive through a convenient door on your left, and begin searching for cleaning facilities... but there are none to be found. You keep trying to get clean, but make no progress. You can hear the party going on, and sometimes even see it, but you always flee when you do because being seen by the gloriously happy people at the party is unthinkable. You spend the entire party this way... hiding, weeping with frustration, shame, and regret... and the party goes forever.
To spell out that parable:
The party is both heaven and hell. The filth is sin. The basic idea is that being in the unfiltered presence of God is incredible bliss if you repent your sins and accept the forgiveness of God through Christ, and unbearable shame otherwise. This is a common idea, with minor subtleties and nuances (eg the nature of eternity - infinite time vs timelessness) proposed by various theologians.
Oh dear.
Someone once said that St. Anselm's ontological argument might as well be
God is that being than whom no more evil being can be conceived.
It is also said sometimes that Christians have the sort of religious philosophy they have because they simply aren't capable to understand anything better.
Anyway, I really do have trouble accepting that fire and brimstone notions could not be true, that they are simply an error or a whip to hold unintelligent people (including Christians) in check.
So much harm has been done in the name of those fire and brimstone notions, so much suffering, so much time and energy invested - that to think that it was all for naught, or nothing but a controlling strategy is very difficult to accept, for me at least.