Rick Warren is the new guru of advice givers, right up there with Dr. Phil and Oprah's latest weight trainer. But there's not much really new about Warren's advice, except its sudden popularity.

Purpose-Driven Life reached number one for several weeks, after six months on the New York Times advice best-seller list. The devotion guide teaches ancient truths, the five purposes of the church—worship, evangelism, discipleship, fellowship, and service—and applies them to the life of the believer. The book is divided into 40 short chapters, each with a 15-minute reading and a Bible verse to memorize.

The genius of the book may be in its subtitle: "What on Earth am I here for?" Warren calls PDL "the anti-self-help book."

The book has sold 4.5 million copies so far. Warren's readers include President and Mrs. Bush, presidential advisers Karl Rove and Karen Hughes, the chaplain of NASCAR, and golfers on the LPGA, according to USA Today.

Warren's book is the basis for a 40-day group study, tested first ...