With all the buzz about Mel Gibson's "The Passion of the Christ," critics suspected that the release of the movie in February would have a significant impact on the film industry--or at least on the box office. Less predictable was the movie's impact on the publishing industry. But well before "The Passion" hit screens, Passion study guides like "The Passion: 100 Questions People Ask About the Movie," a re-release of Sister Anne Catherine Emmerich's 13th-century polemic, "The Dolorous Passion of the Christ," and the official Passion companion book published by Tyndale climbed toward best-seller status.

2004 also saw an abundance of books reacting to Dan Brown's "The Da Vinci Code," the 2003 bestseller. Christian theologians and historians from across the spectrum penned books debunking the "code" and its subtext that Jesus was married to Mary Magdalene. These included Beliefnet columnist Ben Witherington III's "The Gospel Code: Novel Claims About Jesus, Mary Magdalene, and Da Vinci." Other popular anti-da Vinci books were Amy Welborn's "De-coding Da Vinci," Darrell Bock's "Breaking the Da Vinci Code," and "The Da Vinci Code: Fact or Fiction" by Hank Hanegraaff.

Other unlikely best-sellers in the Christian market included Jordan Rubin's "The Maker's Diet" and American Prophecies by Michael D. Evans. "The Maker's Diet" details Rubin's health regimen, based on the foods found in the Bible. "American Prophecies" outlined Evans's vision of the outcome for the U.S. if the government doesn't stop conceding to the Arabs for oil and doesn't fully support Israel's claim to the entirety of the West Bank and Gaza. Meanwhile, Christian televangelist Joel Osteen's "Your Best Life Now," in which he preaches a gospel of abundance, is also maintaining its place on the best-seller lists.

Beyond the Christian book market, Canadian journalist Irshad Manji's "The Trouble With Islam" stirred emotions and debates among Muslims for her call for change within the faith. Claude Anshin Thomas's "At Hell's Gate," a moving and revealing memoir of his days as a GI in Vietnam and his spiritual transformation, was a favorite of many Buddhist readers this year. And the Japanese photography book about the spiritual significance of water, "The Hidden Messages in Water," became an unexpected success after it was featured in the popular film 'What the Bleep?"