Some six million copies of The Da Vinci Code have been sold in the past year. Now there is a wave of books coming to refute the idea 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. 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.” Churches are offering pamphlets and study guides for readers who may have been prompted by the novel to question their faith. Large audiences are showing up for Da Vinci Code lectures and sermons.”