LITTLETON, Colo. --- Evangelical churches across the nation are launching an aggressive effort to save souls by talking about a fictional murder mystery that many regard as blasphemous. Pastors are setting out doughnuts and sandwiches and inviting non-Christians to come discuss "The Da Vinci Code" bestseller. They`re creating hip marketing campaigns to draw nonbelievers to sermons about the thriller. They`re even giving away free iPods loaded with their commentary on the novel. The goal is to instill trust in the Bible and faith in Jesus` divinity --- principles that many Christian leaders believe are threatened by "The Da Vinci Code," which opens in movie theaters May 19 as a film starring Tom Hanks. A poll by Outreach Inc., a church marketing firm, found 68% of its customers, mostly Protestant churches, planned to respond to "The Da Vinci Code" with some form of evangelism. The Catholic response has been ambivalent. Some Catholic groups and a few Vatican officials have urged the faithful to shun Dan Brown`s book and the movie, directed by Ron Howard. But priests expect that many Catholics will see the movie anyway. So hundreds of parishes have set up study groups to pick apart the film`s historical and theological claims. "The Da Vinci Code," which has sold 40 million copies, opens with the murder of a curator at the Louvre Museum. A professor of religious symbology called in to consult discovers clues hidden in the art of Leonardo da Vinci. Racing to unravel the puzzles, he learns that Christianity is built on falsehood: Jesus was not divine; he left an heir by his wife, Mary Magdalene; and the Bible as we know it was pieced together by a 4th century Roman emperor intent on suppressing the role of women in the Catholic Church. If those claims are true, "the Christian faith is a sham," according to a Catholic website that offers priests tips on how to respond to the movie. Though angry, Christian leaders say they have nothing to gain by organizing pickets outside movie theaters. That would make them look closed-minded and defensive, when what they really need to counter the power of the film is "a very positive, wholesome, winsome" response, said Josh McDowell, a Christian writer and evangelist in Richardson, Texas. Besides, "it`s probably going to be an awesome movie," said Garry Poole, a pastor at Willow Creek Community Church near Chicago. Poole drew 22,000 to a sermon about "The Da Vinci Code" last month. He hopes that those who came for the sport of hearing a minister take on a bestseller will return this Sunday for another round. Over time, he hopes they will find truth and comfort in the church and develop an abiding faith. Moved by a similar vision, California pastor Ken Baugh plans to hand out free tickets to "The Da Vinci Code." Other Christian leaders think that`s going too far: "I don`t have to watch pornography in order to be able to dialogue about it," said Matthew Pinto, president of Ascension Press, a Catholic publisher. But Baugh wants to encourage members of his congregation to see the film with non-Christian friends. He plans to give them Starbucks gift cards along with the tickets so they can sit down over coffee when the movie ends and offer their perspective on Jesus. Baugh has already distributed 325 iPod Shuffles loaded with his "Da Vinci" sermons to young members of his congregation so they can give them to friends who do not come to church. "I think the Lord is going to use this film to bring more people to Christ, absolutely," said Baugh, senior pastor of Coast Hills Community Church in Aliso Viejo. At the very least, it has given churches a potent marketing tool. In Littleton, a suburb south of Denver, more than 50 first-time visitors joined 530 regulars at Valley View Christian Church last month when Pastor Gene Barron launched five weeks of sermons on "The Da Vinci Code." (He advertised the series by mailing out 15,000 postcards with an image of the Mona Lisa on one side and a map to Valley View on the other.) Barron opened the first service by quoting an e-mail he had received from someone who had read Brown`s book: "Is the last 25 years I`ve been a Christian all a lie? Is everything I was raised to believe just made up for the money? ... Please help me ... I`m brokenhearted." "You need to know about this story and the potential damage it could do," Barron told his congregation. His sermon, like many on "The Da Vinci Code," was no fast-paced romp through the novel`s intrigues. It presented historical, archeological and theological evidence about key elements of Brown`s conspiracy theory: The Gnostic gospels, the Council of Nicea, the Roman Emperor Constantine, the Priory of Sion. In recent years, evangelical pastors have shied away from such dense sermons, preferring to preach practical self-help messages instead. "The Da Vinci Code" has prompted a renewed interest in basic theology --- to many scholars` delight.