When "The Da Vinci Code" became a publishing sensation, leaders of the Roman Catholic organization Opus Dei realized they had an image problem on their hands.
The assassin in the best-selling thriller is an albino Opus Dei monk named Silas, and the group is depicted as a powerful but secretive cult whose members practice ritualistic self-torture. In a preface titled "Fact," the author, Dan Brown, said his book was more than mere fiction.
When plans were revealed for a movie based on the book, Opus Dei leaders say they tried to persuade Sony Pictures to excise any mention of their group, sending a letter last year saying the book was "a gross distortion and a grave injustice."
Their effort failed.
With the film starring Tom Hanks now set for release on May 19, Opus Dei is trying to sate public interest and cast the group in a very different light than the religious home of a fictional assassin.
The group is promoting a blog by an Opus Dei priest in Rome, revamping its Web site and even arranging interviews with a member said to be the only "real Silas" in Opus Dei - a Nigerian-born stockbroker who lives in Brooklyn.
Silas Agbim, the stockbroker, said that Opus Dei taught its members to hold themselves to the highest standards. "If you do your work well, it's pleasing to God," said Mr. Agbim, a graying father of three grown children who is married to a professor emeritus of library science. "And if you think you will get holy by reciting 10 rosaries a day and doing your work sloppily, that is wrong."
Still, the "Da Vinci Code" movie is sure to revive a long-simmering debate among Catholics over whether Opus Dei is a positive or negative influence in the church. Critics say that while the group is relatively small, a few members seem to hold important positions in the Vatican, including the pope's chief spokesman.
Questions about whether Opus Dei has outsize influence grew when Pope John Paul II granted the group a unique status in the church in 1982, and 10 years later set the group's founder on an unusually speedy track to sainthood.
Opus Dei's reputation for secrecy developed partly because of the group's tradition that members should not publicly proclaim their affiliation. "Is he or isn't he Opus Dei?" guessing games have focused on prominent figures, particularly in Washington.
A controversy exploded last year in England when it surfaced that Ruth Kelly, the young new secretary of education in the liberal Labor Party, was affiliated with Opus Dei. She did not deny it but never clarified her status with the group, prompting even louder criticism. Robert P. Hanssen, an F.B.I. agent who pleaded guilty in 2001 to spying for the Soviet Union, confirmed that he was a member and acknowledged that he had confided his crimes to his priest.
Opus Dei leaders say they are neither secretive, nor particularly powerful, nor lockstep conservatives. They say the group is a decentralized network of more than 84,541 Catholic lay people and 1,875 priests around the world, relatively small numbers in a church of 1.1 billion.
They say they have no aspirations to control the Vatican and believe their calling is to live out their devotion to God by doing their jobs well, be it janitor, senator or full-time mother. Opus Dei is Latin for "the work of God."
Lynn Frank, an Opus Dei member in Walden, N.Y., mother of seven and the owner-entrepreneur of a business that promotes healthful eating, said: "The determination I have definitely comes from my vocation with Opus Dei, because every single day with Opus Dei, you wake up and say, 'I'm giving 100 percent of my day to you, Lord.' And if you slack off, that's a boss you don't want to answer to."
Since its founding in 1928 by a Spanish priest, Josemaria Escriva, the group has found favor with several popes, in particular John Paul II, whose theological emphasis on holiness, the importance of the family and the dignity of work meshed well with Father Escriva's beliefs. In 1982, John Paul granted Opus Dei the status of a "personal prelature," and it remains the only one in the church, meaning that it has its own bishop who reports directly to the pope.
Then in 1992, Father Escriva leapfrogged other candidates for sainthood and was beatified a mere 17 years after his death. He was canonized a saint in 2002.
Joaquin Navarro-Valls, a spokesman for John Paul and now for Pope Benedict XVI, is a member, as was one of the co-authors of a controversial Vatican document released in 2000, Dominus Iesus, on the primacy of Christianity. When the pope wanted to clean up an Austrian diocese where pornography was found on a seminary computer, he appointed a new bishop from Opus Dei.
Also feeding the impression of influence is Opus Dei's American headquarters, in New York, a 17-story building at the corner of Lexington Avenue and 34th Street on which the group spent $69 million for the property, construction and furnishing.
Mention of the location in "The Da Vinci Code" has brought a constant stream of the curious and conspiratorial to the door, said the doorman, Robert A. Boone. He says he tells them, "You think I'd be working here if there were people like Silas walking around?"
Some Opus Dei members are incensed about how the three-year-old best seller presents not only Opus Dei, but also Christianity. In "The Da Vinci Code," a pair of sleuthing heroes discover that the doctrine of Jesus' divinity was made up by the fourth-century Roman Emperor Constantine, and that Jesus married Mary Magdalene and had children.
Mr. Agbim said he had read the book. "It is poison," he said. "It will lead the people to have doubts."
But Opus Dei leaders are taking a less confrontational approach. Opus Dei's United States leader, the Rev. Thomas G. Bohlin, said, "We don't want the controversy to pump up publicity for the movie." Father Bohlin sent the letter to Sony Pictures asking that Opus Dei be left out of the movie and said he had received a "polite but noncommittal" response.
Jim Kennedy, a spokesman for Sony Pictures, said: "We see 'The Da Vinci Code' as a work of fiction and not intended to harm any organization. At its heart the film is a thriller, and we do agree that it really provides a unique opportunity for Opus Dei and other organizations to let people know more about their work and their beliefs."
After researching Opus Dei for a book, John L. Allen, the Vatican correspondent for The National Catholic Reporter, has concluded that its power and wealth have been largely exaggerated. The group's worldwide membership is about equivalent to the number of Catholics in the Diocese of Hobart on the island of Tasmania, Mr. Allen said.
Opus Dei keeps no central financial records, but Mr. Allen determined its assets to be $2.8 billion, a figure the group's spokesmen say appears accurate. Much of that is tied up in the schools and hospitals worldwide. Half of the expense for the New York headquarters was paid for by a single donation of stock, said Brian Finnerty, a spokesman.
"Opus Dei certainly is a growing force in church affairs, and they probably have a very disproportionate number of those church positions that have impact, but let's not mythologize that," said Mr. Allen, author of "Opus Dei: An Objective Look Behind the Myths and Reality of the Most Controversial Force in the Catholic Church."
Some former members accuse Opus Dei of behaving like a cult, with aggressive recruiting and excessive control over members who choose to live in Opus Dei centers. Tammy DiNicola, who joined Opus Dei as a college student and left in 1990 after two years, said the organization pulled in idealistic and very spiritual people by deceiving them.
"They don't tell you you wouldn't spend any holidays with your family, your mail would be read, you would hand over your salary to them, and you wouldn't be able to watch television or radio or even leave the house without permission," said Ms. DiNicola, who helped found the Opus Dei Awareness Network to help former members.
Mr. Finnerty, the Opus Dei spokesman, said that contrary to accusations by some former members, independence and personal freedom were central to the doctrine.
Seventy percent of Opus Dei's members, like Lynn Frank and Silas Agbim, are working people, usually married, who live in their own homes, a category of membership known as "supernumerary." Although they maintain a rigorous schedule of daily prayer and reading, weekly confession and meetings with a spiritual director, they carry on with their lives and professions.
About 20 percent are "numeraries," who give their lives entirely to the organization, living as celibates in an Opus Dei center. Some hold outside jobs, but many work full time in affiliated institutions, like hospitals and schools. Ten percent are "associates," who are celibate but live on their own and not in Opus Dei centers.
Much of the eerie mystique surrounding Opus Dei comes from the numeraries' practice of "corporal mortification." In "The Da Vinci Code," Silas the murderous monk is shown whipping himself bloody and wearing a spiked chain around his thigh so tightly that it draws blood.
In reality, numeraries do wear a "cilice," a chain with points, under their pants for two hours a day. Once a week, they beat their backs with a small cord while reciting a prayer. Opus Dei says corporal mortification is an ancient Catholic practice that promotes penance and identification with the suffering of Christ.
Ms. DiNicola, the former member, said that wearing the cilice was supposed to be optional but that numerary members were made to feel guilty if they did not. "It does cut and it does leave little blood pricks," she said.
Despite the dismal portrayal of their group in "The Da Vinci Code," Opus Dei leaders acknowledge some benefits from the attention. Doubleday, the publisher of the book, is about to release "The Way," a collection of spiritual writing by Opus Dei's founder. Mr. Finnerty, the group's spokesman, said it was "The Da Vinci Code" that opened the door for the deal.