Whether though creating trendy worship services, writing books about how Christ can be seen in current movies, or mirroring hot bands playing on MTV, Christians often try to make their faith more culturally relevant. But Os Guinness says that this desire to be fashionable is exactly why Christians are now becoming marginalized. In a lecture for the C.S. Lewis Institute in 2002, he said that the only thing that is always relevant is the Gospel.

Guinness has written or edited more than 20 books, including The American Hour, The Call, Time for Truth, and Long Journey Home. He's Senior Fellow and vice chairman of the board at the Trinity Forum. His C.S. Lewis Institute lecture has now become his most recent book, Prophetic Untimeliness: A Challenge to the Idol of Relevance (Baker Books).

What exactly is the problem that you defined in your 2002 lecture?

Evangelicalism has never chased relevance more determinedly than it does now. And yet, we've never been more irrelevant. That could be purely accidental, and other factors are behind it, but I would argue that we've pursued the wrong type of relevance. We've fallen captive to modern views of time, progress, timeliness, and relevance. They're leading us down a garden path.

There's nothing wrong with relevance. The gospel, of course, is relevant. But modern views of relevance are dangerously distorted and they'll lead us into trouble. The Bible meets every person's needs. It's never out of date, never old fashioned, and it's always relevant. So I'm not attacking true relevance.

Instead, the problem is this modern idea of relevance. I've argued in other books that the church is being shaped by the modern world. In this book I'm not looking at modernity as a whole, but the modern view ...