Here's my serious, legitimate question about that broad topic.
Why baptize Hitler? Surely there's enough bodies up there in the heavens that we could overlook certain people? If Mr. God thinks we've failed in the spiritual bureaucratical mandatory protocol, he can override and give him a ghost ticket.
(Would you want to share heaven with him? Who would?)
How to make a long answer as short as possible?
Mormons don't adhere to the only heaven or hell concept that other Christians do. Christ said, "in my Father's house are many mansions." Mormons believe there are actually three general degrees or kingdoms of glory - the celestial, terrestial, and telestial. I'll forego breaking that down more.
Mormons also don't believe in a neverending state of hell like other Christians do. There certainly is a hell. It's always been there, and always will be. So, in that sense, it is eternal. But somebody is only there until they've paid "every last farthing."
Somebody like Hitler is a classic example. He will have to suffer in Hell but, eventually, that suffering will have run it's course. Eventually, Mormons believe, even somebody like him will get to the point where - through the Atonement of Christ and the ordinances of his Church (of which baptism is one) - they are freed from the "buffetings of Satan." That doesn't mean they then get to enter into God's presence in the celestial kingdom. But somebody like Hitler, besides being resurrected, will eventually enter into the the lowest kingdom - the telestial kingdom.
Again, I say this, not to proselytize, but to clarify.
