Belmont, USA - Stepping into a Mormon temple is like watching a cinematic take on heaven: everything glows in white -- from the rich upholstery to the ivory outfits of worshipers and polished marble floors.
It's also a step more people are taking in the heavily Roman Catholic U.S. Northeast, where Mormon numbers have jumped 37 percent in 10 years, nearly double the religion's national growth rate of 21 percent, church data show.
"The number of new members here is just utterly amazing," said Allan Barker, president of the Massachusetts temple of the Church of Jesus Christ of Latter-day Saints, as the faith is formally known.
The once-isolated sect based in Salt Lake City, Utah, is now one of the world's fastest-growing and affluent religions, with 12.3 million members globally. More than half live outside the United States, including a flourishing Latin American flock.
Sociologist Rodney Stark, who predicted in 1984 that Mormonism would eventually rival Catholicism, Islam and other major religions with 267 million members worldwide by 2080, said aid lavished on new converts by a lay clergy rooted in international business and other top-tier professions explains much of the global appeal.
"The fact that the church provides substantial social services is very attractive, especially when you start getting into places where social services are really lacking," said Stark, author of "The Rise of Mormonism."
"Mormons tend not to ever appear on the welfare rolls because the church tends to step in and take care of them," he added. "Elderly people will get their houses painted by a group of guys from the local church over the weekend. There's a lot going on there that doesn't meet the eye."
Church officials and religious scholars attribute its growth in the Northeast to a steady influx of Hispanic worshipers, the allure of top-flight universities in Boston and New York, and to turmoil in the Roman Catholic Church following a clergy sexual abuse scandal that erupted in Boston in 2002.
"Catholicism has stumbled," said Jan Shipps, president of the American Society of Church History, adding that Massachusetts's Mormon governor -- potential 2008 White House contender Mitt Romney -- also boosted the church's profile.
Tim Wilson, a 31-year-old former Catholic, said news that U.S. bishops moved priests known to have abused minors to new parishes instead of defrocking them sealed his decision to join the Mormon faith in December 2002.
"I didn't have any vested interest in belonging to an organization that would conduct such an awful situation among its priests," said Wilson, a research executive.
However the Northeast's 333,000 Mormons remain vastly outnumbered by its estimated 20 million Catholics.
But the expansion marks a historical triumph in a region where Joseph Smith, a Vermont native, founded the sect in 1830 in upstate New York a year before being persecuted and forced to flee to the Midwest.
But as it expands, Barker and other Mormon leaders are quietly bracing for a possible new threat to the church's image.
"Big Love," a new series on cable TV channel HBO about a fictional polygamous family headed by a Viagra-popping husband in Utah, casts light on its awkward and embarrassing ties to polygamy, which the Mormons practiced before the Civil War then banned in 1890.
"The show has to be a negative," said Barker. The central characters are not Latter-day Saints and Mormons who commit polygamy are excommunicated, he noted, echoing a point recently reinforced by a statement from church headquarters in Utah.
Mormon leaders have spent decades countering critics who dismiss the faith as a cult and a threat to Christianity. They distance themselves from about 30,000 breakaway Mormons in Utah and nearby states who practice polygamy illegally, as well as the many excommunicated Mormons in polygamous marriages who still identify with the faith.
Founder Joseph Smith took at least two dozen wives, say historians. His successor, Brigham Young, had about 20. The custom was officially banned when Washington, angered by its spread, threatened to deny statehood to Utah.
Today, about 30,000 missionaries -- often young men in business suits walking the world's streets in pairs -- project a wholesome, family-oriented image that has helped swell global Mormon adherents by 36 percent from 1995 to 2005.
Under the faith's tenets, alcohol, caffeine and tobacco are banned, while no one goes to hell.
Exactly how the clergy sex-abuse crisis has played into Mormon numbers growth in the Northeast is unclear, scholars say. The last formal survey of the Catholic population in the region was held in 2001, a year before the scandal surfaced.
Some 90 percent of about 900 members of the six-year-old Mormon temple in the Boston suburb of Belmont converted from other religions. Barker declined to say how many had been Catholics.
But doctrinal similarities with Catholicism could account for some of the expansion, Shipps said.
Like Catholicism, Mormonism offers clear-cut answers to big theological questions. In contrast, she said, American Protestantism offers greater room for spiritual debate.
Barker, 79 and a Utah native, recalls the suspicion he faced in Boston in the early 1950s. Once, when a furniture saleswoman found she was talking to a Mormon, she turned to Barker's wife and exclaimed: "How could you live with this man?"
"Here we are 50 years later," he said. "It's remarkable how much things have changed."