Michael Patton tackles the question, why do we love C.S. Lewis and hate Rob Bell? I agree with his analysis. Read his post here. Below are some key points ... and these are important since many of Bell's defenders use the difference in our response to Lewis and Bell as a sign of hypocrisy; it is not - they just do not understand the argument. Patton does a nice job explaining that difference.
First of all, no one hates Rob Bell (or at least, no one should).
... while C.S. Lewis has a great deal of theological foibles, his ministry is defined by a defense of the essence of the Gospel. The essence of who Christ is and what he did are ardently defended by Lewis, saturating every page of his books. His purpose was clear: to defend the reality of God and the Lordship of Jesus Christ. All other things set aside, this is what you leave with every time you read Lewis. The problematic areas are peripheral, not central. One has to look hard to find the departures from traditional Protestant Christianity. They are not the subjects of his works and do not form the titles of his books.
However, with Rob Bell, the essence of who Christ is and what he did seems to be secondary. One has to look for those things as they weed through his defenses of non-traditional Christianity. Whereas Lewis’ ultimate purpose is to define and defend “mere” Christianity, Bell’s “mere” Christianity is but a footnote to a redefined Christianity. Bell’s focus is to challenge, question, change, reform, and emerge from traditions that bind us. Traditional apologetics, orthodoxy, and foundations are brought into question from beginning to end. Christ’s reality, deity, exclusivity, and the hope of the Gospel proclaimed receive an occasional footnote (if at all) from Bell.
Another way to put this is to say that in the ministry of C.S. Lewis, the central truths of the Christian faith are the chorus of his songs, with the occasional problem in the stanzas. However, with Bell, the chorus of his song is filled with challenges to traditional Christianity and if you listen really closely to the stanza, you might get an occasional line of orthodoxy.
... it is not just Rob Bell that is at issue. There are dozens of popular writers, pastors, bloggers, and authors who are singing the same chorus. They give lip service to the essence of Christianity, but from their platform it is only peppered in here and there. I think this is the core problem with what is/was known as the “emerging church.” It is not that we are against rethinking, reimagining, reforming, or any other “re,” it is that this became the central focus of the movement. Christ, the cross, sin, righteousness, and all other elements that create the essence of who we are became the subjects of challenges – mere lines in the song. This is why I distinguish between, say, Brian Mclaren and Dan Kimball. Both men, early on, were considered part of the “emerging church.” However, though he challenges some ideas here and there, Dan Kimball (like C.S. Lewis) is committed to the essence of the historic Christian faith. Truth, doctrine, love, and righteousness are found in everything he writes and says. They are the chorus. With Mclaren, on the other hand, traditional Christian beliefs and practices form more of (what seems to be) an embarrassing afterthought that he proclaims only under duress.
This is why I don’t like comparing C.S. Lewis to Rob Bell. There is no comparison. Neither is it fair to team Rob Bell up with many of the great saints of the past, such as the Cappidocians or Origen (as is often done). Yes, they all have problems, but the question is, Do these problems define the essence of their ministry and passion? With Rob Bell (and many like him), they do. With most of the other historic figures that some try to put on Bell’s team, they don’t.