Many Christian leaders today have abandoned Jesus' teachings for their own "reformed" theology. For these people, Jesus' words aren't good enough so they invented their own teachings to benefit themselves. They call it doctrine and they worship their precious doctrine over Jesus himself. Then Rob Bell comes along and shatters their world by going back to the Bible and back to what Jesus actually said and back to what the first Christians actually believed.
The most important message from Rob Bell's book is that you don't get saved by believing in hell. You get saved by believing in Jesus and living the life that Jesus told us (and showed us) how to live.
Throw away all the noise and the junk cluttering up the Christian church today and get back to what Jesus actually said in the Bible. Ignore those false teachers who desperately want you to worship their own tremendous ego and their big money hungry organizations and their precious self-declared "doctrine". Don't waste your time on those things instead of worshipping Jesus himself.
How do you know when you are being lead by a false teacher? Simple. He doesn't like to confess his own sin. He is constantly talking about the sins of others, or whether others are going to hell or not, or whether other denominations such as the Mormons are cults or not, while completely ignoring his own sin. Don't give these people your time or your money.
Another good way to figure out if you are being lead by a false teacher is that they quote everyone except Jesus in the Bible. Its easy to twist and spin the words in the Bible to say anything you want it to say especially if you ignore the words that Jesus actually said. If they call themselves "Christians" then why do they ignore what Jesus said? Think about that for a while.
The third way to identify a false teacher is when they whine and complain about Rob Bell. They don't like Bell and claim he is "dangerous" because Bell is casting away all the junk that has been built up in the Christian church over the last many years. Bell is taking us back to the bible and back to what Jesus actually said.
Don't worship churches, or books, or self appointed religious fanatics who have arrogantly invented their own "doctrine" and put it above God himself. These things will not do you any good on the judgment day. Worship only Jesus and follow only what he said.