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 LDS 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 LDS 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 governing body of the church. "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."