Is Hell eternal, or do some/all escape it? In his recent book, Love Wins, author and pastor Rob Bell caused quite a bit of controversy (and anger) by making the argument that Heaven is the state that we are in when we follow God's will and Hell is the state we are in when we follow our own will, and that after death there is no reason to think that we will continue on in these state. He argues that we obviously have the choice to follow God's will our or own in life, but it is debatable if that decision will be available after death.

He essentially cites every single mention of Hell in the Bible and makes the case that most are fairly ambiguous when it comes to the eternal state of those who die rejecting God's will. He explains that a lot of the modern imagery of hell is a product of the middle ages, and is not in fact Biblically based (Satan is the ruler of hell, etc). I couldn't help but notice he did not mention several versus that did not mention hell explicitly, but which clearly reference it and seem to make clear it is eternal. 

He also went on to cite a number of versus that indicate that God wants everyone to be saved and ask the question 'Does God get what he wants?'


  who wants all men to be saved and to come to a knowledge of the truth


1 Timothy 2:4

So, is it debatable? Are there any denominations which do not place those who rejected or never heard the gospel in hell forever? Is it heretical to believe that some non Christians will not be in hell forever?
According to scripture, hell is real, and anyone who was not born again will not enter the Kingdom of Heaven.


  41“Then he will say to those on his left, ‘Depart from me, you cursed, into the eternal fire prepared for the devil and his angels.
  42For I was hungry and you gave me no food, I was thirsty and you gave me no drink,
  43I was a stranger and you did not welcome me, naked and you did not clothe me, sick and in prison and you did not visit me.’
  44Then they also will answer, saying, ‘Lord, when did we see you hungry or thirsty or a stranger or naked or sick or in prison, and did not minister to you?’
  45Then he will answer them, saying, ‘Truly, I say to you, as you did not do it to one of the least of these, you did not do it to me.’
  46And these will go away into eternal punishment, but the righteous into eternal life.” - Matthew 25:41-46 ESV
  
  14Then death and Hades were thrown into the lake of fire. The lake of fire is the second death.
  15If anyone’s name was not found written in the book of life, he was thrown into the lake of fire. - Revelation 20:14-15


This clearly states that anyone who does not follow Christ and accept Him into their heart will go to hell. It's inconvenient, but nowhere does it say that following him will be convenient. Anyone who thinks they have an expert knowledge of God is silly. God is too big for man to understand. We have the gift of prayer and his word to find answers in.

Francis Chan did a wonderful job of explaining this on YouTube.