By Eric Marrapodi, CNN Belief Blog Co-Editor

Washington (CNN) - The scene at a Mormon congregation here on a recent Sunday would surprise Americans who think of Mormons as young white missionaries in stiff white shirts, black ties and name tags.

Yes, there are white missionaries handing out bulletins at Washington’s Third Ward - what Mormons call their congregations - but there's also Ruth Williams, an elderly African-American woman, decked out in her Sunday best, doing the same.

White, black, Asian and Hispanic Mormons mingle before the service begins. As it gets under way, an African-American tween plays a video game on his smartphone in one pew as a 30-something white woman across the aisle taps away on her iPad.

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On this Sunday, the Sacrament - what Mormons call the remembrance of the Last Supper and what other Christians call Communion - is said in French, a nod to the area's burgeoning West African population.

It is not a special multicultural celebration Sunday. For this growing Mormon congregation in northeast Washington, it's just another weekend.

“It’s 30% Caucasian, 30% African-American, and the rest is a combination of first-generation immigrants from around the world,” says Bishop Robert Nelson, the lay leader of this congregation.

Washington's Third Ward is a near mirror image of the diverse neighborhood it serves, jarring with the Mormon Church's image as a faith-based club for upper-class whites.

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And the Mormon Church, officially called the Church of Jesus Christ of Latter-day Saints, says the ward represents the diverse face of modern Mormonism, a message it has been trying to spread as part of a yearlong nationwide push to counter its lily-white image.

Since January, the LDS Church has spent millions on an "I'm a Mormon" advertising campaign that features television commercials, billboards and bus signs with Mormons from African-American, Asian, Latino and other ethnic backgrounds. Just last month, the campaign entered 11 new major media markets in Texas, Indiana, Nebraska, Washington, Georgia and Arizona, hitting cities like Atlanta, Denver and Phoenix.

(You won't be seeing the ads in Iowa, South Carolina or Florida. With Mitt Romney and Jon Huntsman, both Mormon, competing in the Republican presidential primaries, the church says it wants to steer clear of politics.)

The Mormon Church even used the ad campaign to launch a shot across the bow of the hit Broadway musical "The Book of Mormon," buying a digital "I'm a Mormon" billboard just down the street from the theater where the show is playing.

The musical satire, co-produced by the creators of the television show "South Park," shows earnest white American Mormon missionaries and their misadventures in proselytization in Africa.

But the billboard shows a very different face of Mormons. There is an African-American couple playing Frisbee on the beach, a Latino grandfather and granddaughter, a goateed motorcycle sculptor.

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An official church website, Mormon.org, lets those interested in the church search for Mormons from diverse ethnic backgrounds and features videos from the likes of black soul singer Gladys Knight and Brandon Flowers, frontman for the rock band The Killers.

"It's to say, 'We're like you,' " said Kathleen Flake, a religious scholar from Vanderbilt Divinity School. "It's an attempt to combat stereotypes so that absolutely people are more open to see the normalcy of Mormonism."

The LDS Church says its attempt at an image makeover is as much a reflection of demographic reality as it is a PR effort. While young white missionaries may still be Mormonism's public face in the United States, they are no longer fully representative of the Salt Lake City-based church.

“Our doctrine is we’re all sons and daughters of God," says Stephen Allen, managing director of the LDS Church's missionary department. "Skin color or anything else is not a significant issue to us.”

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As head of global missions, Allen supervises the 52,000 19- to 25-year-old missionaries knocking on doors around the world.

He's also executive director of the “I’m a Mormon” campaign, which began in nine markets this year.

“In terms of targeting, we’re not specifically targeting or avoiding any particular group," Allen says. "We send our missionaries all over the world to anywhere people will listen.”

As the church’s efforts to win converts has expanded internationally, “following the American flag around the world,” as Flake puts it, the LDS Church has grown more diverse.

“We’re in most of the free world right now,” Allen says. "We have a presence in Russia and Ukraine and the Baltic countries. We have a growing presence in Africa ... Nigeria, Kenya … then we have, Japan, Korea, Taiwan. There are small congregations in India, and the church is growing in those places.”

The church's membership has doubled since 1988, to 14.1 million Mormons worldwide. Six million Mormons live in the United States. Many of the church's members live in the American West and Northwest, in some of the whitest states in the country.

But like many other churches, there has been explosive growth in the LDS Church in Latin America. There are more than a million Mormons in both Mexico and Brazil. There are nearly a million Mormons in Asia and 300,000 in Africa, according to church statistics.

“This attempt to emphasize diversity and to emphasize a wide range of people who are Mormon does reflect, in a lot of ways, what’s been going on in reality for a while,” says Matthew Bowman, an editor at a Mormon studies journal called Dialogue.

Even in the United States, the perception of who Mormons are has changed.

“We’ve done a lot of research to see what people think of us and what their perception is,” Allen says. “Twenty-five or 30 years ago, if you said, ‘When you think of the word Mormon, what comes to mind?’ the answer would have been Mormon Tabernacle choir, polygamists, racists, the Osmonds [singers Donny and Marie].”

While that's less the case today, Allen says many people still don't know what a Mormon looks like - or don't know that there are Mormons from minority backgrounds.

A spokesman for the church said it doesn't keep statistics on members' race or ethnicity.

But “it’s no longer just a predominantly white church,” Allen says. “In our early history, you know, it was founded in upstate New York in the United States and was very much a white congregation, but today it’s very diverse.”

The complexion of the average Mormon ward reflects the neighborhood where the building resides. “Mormon wards are not self-selecting,” says Richard Bushman, a visiting professor at the School of Religion of Claremont Graduate University. “In Mormon congregations, they are just geographical boundaries, and wherever you live, you go to church.”

There is no church shopping. Congregants can’t go to another ward if they don’t like the music or the doughnuts at the social hour, as in many other faith traditions.

In Washington's Third Ward, two new converts who had recently been baptized were welcomed into the church on a recent Sunday. Both women were young African-Americans. The men who formed a circle around them and prayed over them were all white.

Unlike the ward, the church's global leadership in Salt Lake City is mostly white.

It was not until 1978 that African-Americans could serve in priesthood positions in the church, a prohibition that extended back to Mormon leader Brigham Young in the 1850s.

"When you see in that ad campaign Mormons, including African-Americans, they are trying to communicate against that stereotype that Mormons are racist, there's no question about this," says Vanderbilt's Flake. "They are trying to say, 'That's not fair. That is not who we are. Even if we were, we are not now.' "

Allen says the "I'm a Mormon" campaign was designed to assist the small army of young Mormon missionaries out knocking on doors.

"Our feeling was anything we could do to help them was really important," he says. "And helping them means softening people’s hearts.”