PROVO, Utah - Every Wednesday, hundreds of young Mormon men and women not far removed from high school arrive on the campus of Brigham Young University, where they are severed from family and text-messaging and entrusted with the very future of their faith.
Sequestered in classrooms for 14 hours a day, these missionaries-in-training are taught to boil down core doctrines to make them understandable and consistent, whether their audience is in Utah or Uganda.
But increasingly, classroom conversations at the Mormon church's flagship Missionary Training Center have centered not just on winning new believers but on keeping them - a topic looming as a critical challenge for whoever is picked to succeed church president and prophet Gordon B. Hinckley, who died Sunday at 97.
Although retaining members is a challenge for all evangelizing faiths, the Mormon church appears to have a particularly poor retention rate in some countries.
The foreign retention rate is critical to the future of the Mormon church. An American-born denomination, the Church of Jesus Christ of Latter-day Saints now boasts more members abroad than at home - about 55 percent of the world's 13 million Mormons live outside the U.S., according to church figures.
The Mormons are working hard to maintain doctrinal integrity and still compete in the spiritual marketplace for converts. The effort is playing out at the Missionary Training Center, which is equal parts language lab, college dorm and proselytizing think tank.
The largest of 17 such centers around the world, the 4,000-capacity Provo MTC trains young men and women for three to 12 weeks. The length of stay depends on whether the missionary is learning one of the 53 languages taught here and its degree of difficulty.
All able Mormon men are expected to embark on a two-year mission at 19. The center's halls teem with polite young men who wear dark suits and washable polyester ties they swap like trading cards in the mission field. There is a smattering of women preparing for 18-month trips.
The closest thing to a student union is a basement laundry room, where missionaries on their day off, or Preparation Day, relax in jeans and sweat shirts and write weekly letters home. Or they can send e-mail, though no more than 30 minutes on the Internet is allowed.
Brock Hale of Medicine Hat, Alberta, described training that goes beyond the language and doctrine he needs to engage potential converts in Romania.
His teacher, a returned Romanian missionary, provides crucial cultural advice: Be prepared for the difficulty of selling Mormonism's prohibition against smoking, and don't be easily offended by Romanians, who are bold and quick with insults.
For years, Mormon missionaries mastered a script that began with church founder Joseph's Smith first vision. Hinckley, concerned with low retention, introduced a new approach called Preach My Gospel, which urges missionaries to speak more from the heart.
"To have a rote, memorized script, it doesn't work for everyone," said Malachi McGee of Burns, Ore., a missionary bound for Taiwan.
The Mormon church does not publish retention figures, and it is hard to make comparisons because denominations count their members and measure participation differently.
Timothy Heaton, a BYU sociologist, used census data from Mexico, Brazil and Chile to show the number of citizens who claim Mormonism as their religion there was only 20 to 25 percent of the church-reported membership figures, suggesting low retention.
Some scholars suggest the church is struggling to retain members because it resists accommodating the cultural trappings of other countries. The Roman Catholic Church, in contrast, has allowed drumming in African parishes, something Mormon leaders frown on.
Even in the African bush, Mormon missionaries still wear white shirts and ties. And designs for Mormon meetinghouses are conceived in Salt Lake City.
"It's like a McDonald's that stands out in Tokyo," said Jan Shipps, a prominent non-Mormon scholar of the religion.
Others believe that although the Mormon church describes itself as a universal faith, American aspects of its theology are probably costing it members in other countries.
"God's prophet was a New Yorker, the Garden of Eden is here in the states, and Christ is to return in Missouri," said Gerald McDermott, a professor of religion at Roanoke College in Virginia. "At a time when America is not really popular overseas, that's not going to win friends and influence a lot of people."
Then there are the demands of the faith that can turn away some - such as tithing 10 percent of one's income and forsaking coffee, which is a big part of Latin American culture.
"Becoming a Mormon if you live in California is hard enough," said Richard Bushman, a Mormon scholar and professor emeritus at Columbia University.
There are signs of change: Missionaries are now urged to spend more time following up with new believers. Also, the church's online disaster preparation manual urges storing not just wheat but rice.
And in a recent broadcast of a worldwide training meeting, some Mormons noticed that a church apostle sitting alongside Filipino church officials wore not the standard suit and tie but a short-sleeve dress shirt. He still wore a tie.
"The different kinds of people around the world, they will keep their personality and their traditions," said Dieter F. Uchtdorf, a member of the Quorum of the Twelve, a top Mormon governing body. "The point is that the core doctrine brings the members together."
A Czech-born German who was head pilot of Lufthansa airlines, Uchtdorf is the only member of the Quorum of the Twelve born outside the United States. He said Mormon retention is remarkably high given that the church relies on a lay, unpaid congregational leaders.
Uchtdorf also said that in areas with fast growth potential, the church must grow "slowly and in a natural, healthy way" so that local congregational leaders are well grounded in doctrine.
"In some parts of Africa, we could baptize full villages," said Uchtdorf, 66. "We could immediately explode our membership. We're going slowly to have sufficient leadership."