Midway through a conference deep in the US Midwest, a neat man in his thirties is strutting up and down a stage which he shares with an actor, dressed as an Old Testament high priest and holding a small goat on a leash.

As the audience watches, the neat figure issues a crisp expository sermon on Christ’s dual role as both sacrifice and high priest. Towards the end, the sin-carrying goat is released while the high priest walks slowly to a chair and sits down; demonstrating Christ’s completed atoning work.

Whistles, whoops and loud applause fill the auditorium at what had been an unforgettable illustration of a complex and intricate biblical doctrine.

The speaker is Rob Bell, teaching pastor at Mars Hill Bible Church in Michigan and the author of a bestselling book, Velvet Elvis. He has grown in popularity ever since starting Mars Hill Church in 1999. Within a year it had moved into a shopping mall and by 2005 it had its own 3,500-seat home running three services on a Sunday.

He has also produced a series of short films, under his Nooma banner, exploring themes such as forgiveness, love, wealth and guilt. Nooma takes its name from the Greek word “pneuma”, meaning spirit or wind, and has been used by churches around the globe to reach the media generation.

Bell, now busy promoting his second book, Sex God, has been hailed as the “next Billy Graham” and a rising star in Western evangelicalism. But his popular teaching and philosophy have begun to ruffle a few feathers, in particular among conservative evangelicals who find him more show than substance. Of course, the 10,000 who attend his church every Sunday would differ.

In Velvet Elvis Bell discusses the ancient rabbinic method of teaching and asks his readers to do the same. In Jesus’s day, he argues, no one read the Scriptures on their own, it was a communal activity and people interpreted it together — it was an activity far removed from much Bible teaching in our individualistic Western culture.

“Many pastors study alone all week, stand alone in front of the church and talk about the Bible,” Bel says, “and then receive mail and phone calls from individuals who agree or don’t agree with what they said.”

This works for some, he says, but it is not the only way. For example, when Jesus talked about “binding and loosing” (in Matthew xvi, 19, for example) it meant that a group of followers decided what scriptural interpretation to “bind” and which ones to “loose”. If one individual is carried away with an interpretation the rest of the group is there to put him straight.

Understanding the Bible is an unfolding process, Bell insists, rooted in dialogue and discussion. This idea is at the centre of Velvet Elvis. “Just because I’m a Christian and I’m trying to articulate a Christian worldview doesn’t mean I’ve got it nailed,” he writes. “I’m contributing to the discussion. God has spoken, and the rest is commentary, right?”

Not according to Don Carson, the author of more than 45 books and a leading US evangelical thinker. He says that location is a key factor in Bell’s popularity: “He serves in Grand Rapids — home of many Reformed churches, many of them very traditional and more than a little stuffy. To people from that background, Rob is a breath of fresh air.”

Carson contrasts him to Mark Driscoll in Seattle who, curiously, also runs a large church called Mars Hill. Driscoll, unlike Bell, responds to the “postmodern turn” by being “unwaveringly confessional” while remaining contemporary in speech and worship styles. Bell, on the other hand, is a “work in transition”, Carson says, who is less reflective on the concept of sin and how to communicate it.

Carson believes that Bell is representative of the “emerging church” movement in the US, a group of postevangelicals who refuse to define Christianity in abolutes but rather as a growing and developing entity. Key emergent Christian thinkers include Mike Yaconelli (the editor of Stories of Emergence) and Brian McLaren. They tend to view faith as a conversation instead of a set of beliefs and as a journey in place of dogma.

Troubled by aspects of their movement, Carson recently wrote a book, Becoming Conversant with the Emerging Church, which puts the genre under the microsope so that readers can spot “emergents” when and where they appear.

Bell has carefully distanced himself from the “emergent” label. “I never use that word,” he says, “because it doesn’t help people. It creates a category of labels that get us off the point, which is ‘what is Jesus up to in the world today and how can we join Him?’ ” According to his new book Sex God, what Jesus is clearly up to is talking about relationships and human sexuality. Here Bell argues that sexuality is a much broader term than we might once have believed. “It’s about the truth that our skin and our souls are connected,” he says. “God created us integrated beings, and what we do with our physical self cannot be separated from our hearts and minds and souls.”

The word sex, he observes, comes from the Latin word secare, meaning to sever or cut off. Human beings have known the severed nature of this relationship, Bell believes, since the Fall.

“Our sexuality is our awareness of how profoundly we’re severed and cut off and disconnected,” he says. “Our sexuality is all of the ways we go about trying to reconnect.”

With this knowledge even celibate individuals are profoundly sexual. “As one writer put it: Mother Teresa was a terribly erotic woman. She gave herself to the poor. Instead of loving one, she chose to love, to connect with many.”

Bell insists that he is no shock jockaiming to provoke . Rather, he claims that his unique ministry is about “repainting the Christian faith” while delving deeper into its rich Judaeo-Christian past.

With Carson and other evangelical luminaries on his case Bell may have to be more careful about how he “repaints” that faith.