Hell is the core of Christianity; it is what Jesus came to save us from. We all deserve to go there, and there is only one way to escape: believe the right things. (Just what those things are depends on who you talk to.) And if for whatever (and however good a) reason you should die without that belief, you will be tormented forever in Hell by the God who loves you. It is as simple, cruel and absurd as that.
Here is what Charles Darwin said about it in his autobiography:
I can hardly see how anyone ought to wish Christianity to be true; for if so, the plain language of the text seems to show that the men who do not believe, and this would include my Father, Brother, and almost all my best friends, will be everlastingly punished. And this is a damnable doctrine.
It was Hell that did me in as a Christian. I, like Darwin, couldn't believe that my family and friends and billions of other nonbelievers (and religiously incorrect believers) would be tormented forever in Hell for their honest disbelief. It amazes me that anyone could.
Hell is indeed a damnable doctrine. Darwin, as usual, had it exactly right.