Evil = Broken

Hollywood and writers of today, and yesterday have warped the concept of evil until it has basically no meaning. In fact, popular culture equates evil with mischief, but evil is something much different. Evil is a measure of how broken something is. Corruption is not an addition of a malevolent force, but rather a good thing that has broken. I've been reading Stranger in a Strange Land, by Robert Heinlein. In it the Arch-Angel Foster is talking about an alien species with a "tripolarity" and he says:

I have it on High Authority that Don Juan himself could not manage to take Earthly interest in any of their three polarities... that's not an opinion; he was borrowed as a test. He screamed, and prayed to be returned to the solitary hell he has created for himself. Robert Heinlein - Stranger in a Strange Land Pg 343

It is sorta in passing, but the statement "created for himself" I think explains alot about how hell works, and why people are sent there. These people are broken, and could hurt others, like a Black Hole. The only way to repair a Black Hole is to wrap space around them, so it consumes itself. Evil people are that broken... that they have to be cut off so they can't consume other people. Hell is not a luxury that an all powerful God gets to indulge in so He can give these terrible people their "comeuppance" for eternity. Hell is a necessity to keep these broken people from harming the people that God has chosen to fix.