Fearing that the best-selling novel "The Da Vinci Code" may be sowing doubt about basic Christian beliefs, a host of Christian churches, clergy members and Bible scholars are rushing to rebut it.

In 13 months, readers have bought more than 6 million copies of the book, a thriller with a plot that Christianity was founded on a cover-up — that the church has conspired for centuries to hide evidence that Jesus was a mere mortal, married Mary Magdalene and had children whose descendants live in France.

Word that director Ron Howard is making a movie based on the book has intensified the critics' urgency. More than 10 books are being released, most in April and May, with titles that promise to break, crack, unlock or decode "The Da Vinci Code."

"Because this book is such a direct attack against the foundation of the Christian faith, it's important that we speak out," said the Rev. Erwin W. Lutzer, author of "The Da Vinci Deception" and senior pastor of Moody Church in Chicago, an influential evangelical pulpit.

The Rev. James L. Garlow, co-author with professor Peter Jones of "Cracking Da Vinci's Code" and pastor of Skyline Wesleyan Church in San Diego, said, "I don't think it's just an innocent novel with a fascinating plot. I think it's out there to win people over to an incorrect and historically inaccurate view, and it's succeeding. People are buying into the notion that Jesus is not divine, he is not the son of God."

Among "The Da Vinci Code" critics are evangelical Protestants and Roman Catholics who regard the novel as another infiltration by liberal cultural warriors. The critics and their publishers are also hoping to surf the wave of success of "The Da Vinci Code," which has been on The New York Times hardcover fiction best seller list for 56 weeks. There are 7.2 million copies of the book, published by Doubleday, now in print.

Dan Brown, a former teacher who wrote "The Da Vinci Code," is declining all interview requests, his publisher says, because he is at work on his next book. But Brown says on his Web site that he welcomes the scholarly debates over his book. He says that while it is a work of fiction, "it is my own personal belief that the theories discussed by these characters have merit."

The plot of "The Da Vinci Code" is a twist on the ancient search for the Holy Grail. Robert Langdon, portrayed as a brilliant Harvard professor of "symbology," and Sophie Neveu, a gorgeous Parisian police cryptographer, team up to decipher a trail of clues left behind by the murdered curator at the Louvre Museum, who turns out to be Neveu's grandfather.