As the somber notes of the hymn sounded from the organ, the parishioners of St. John's Episcopal/Anglican Church filed to the altar to receive Communion and a blessing from the priest.

Then it was time to get down.

Clapping in rhythm, the priest and congregation of more than 200 people, most of them African and Caribbean immigrants, burst into the song "Jesus Never Fails." Women wearing vibrantly patterned tunics danced down the center aisle. Two choir members shook castanets, and one man banged a small drum. A handful of older, white parishioners, who had started attending the church decades ago when it was a predominantly white crowd, refrained from clapping -- though they couldn't help but bob their heads to the beat.

The scene at the 94-year-old Prince George's County church captured the distinctly African influence that is sweeping into many area worship services. Christianity is growing faster in Africa than on any other continent. And as the number of immigrants from Nigeria, Liberia, Ethiopia and Sierra Leone grows, the fervor of African worship is being infused into churches here.

About 100,000 African-born people live in the Washington region, a major immigration hub that is home to about 10 percent of the total U.S. population of Africans. Scholars estimate that about half are Christians, and the rest are Muslims or practice indigenous African religions.

Betty Klimek, 64, said the services at St. John's have become less formal than what she was used to, but "they're not that drastically different."

"My only objection is to the wine; it's a little stronger than I like," she said of Communion. "But they believe in God. The thing the church is supposed to do is to help the people who are there. In our case, the people are just from different parts of the world."

In fact, scholars say, the African immigrants' brand of Christianity hark back to traditions that once held sway at many mainstream U.S. churches but that have faded over several decades. With services that typically run at least two hours, the African Christians tend to emphasize evangelizing, a more literal reading of the Bible and a conservative stance on such social issues as gay marriage.

Jacob Olupona, a professor at the University of California at Davis who is a leading scholar on African churches, calls the immigrants "reverse missionaries."

The majority of African Christians in the United States are Pentecostal and are rapidly planting churches across the country. Many others belong to the Anglican Communion -- which has half its worldwide membership in Africa -- and have joined Episcopal dioceses in the United States.

"They're bringing a revitalization of spirituality," said Olupona, whose father was an Episcopal priest in Nigeria. "For centuries, the West took Christianity to Africa. The Africans are now of age and of the position to bring Christianity back to the West."

Most of the region's African immigrants arrived in the past 15 years, partly because of the U.S. government's issuance of "diversity visas" to a wider range of nationalities. The majority speak English and are well-educated professionals, enabling them to adapt to their new homes more quickly than other immigrant groups have.

Until about a decade ago, St. John's, a small stone church in downtown Mount Rainier, had a congregation that was becoming smaller and aging. Now, children fill the Sunday school classes, the choir has formed again and the church newsletter has gone back into production. About 100 Nigerian immigrants attend the Igbo-language service, and parishioners from Sierra Leone, Ghana, Liberia and the Caribbean join the white and African American congregants at the English-language service. Just one member of the church leadership is white; the others are African immigrants.

Even at some predominantly white Episcopal churches, African immigrants have key leadership positions. At Episcopal Church of the Ascension in Gaithersburg, where less than one-quarter of the nearly 600 parishioners are African and Caribbean immigrants and there is no foreign-language service, the senior warden this year is a Liberian immigrant.

Other African newcomers have planted offshoots of churches based on their home continent. Bethel World Outreach Ministries International, a nondenominational church in downtown Silver Spring, is connected to a church in Liberia and was formed in 1990 by a handful of refugees who had fled civil war. The church boasts more than 2,000 members from various African nations, with services in English and French.

Half a mile away, the eight-year-old Jesus House, DC attracts more than 1,000 people to its weekday and Sunday services, which are conducted in English. The Pentecostal church, with a sanctuary of glass and brick, is the largest of about 80 parishes in the United States that have ties to the Redeemed Church of Christ in Nigeria. Most members are Nigerian immigrants, but there are some from the Caribbean as well as some African Americans.

The church's minister, the Rev. Ghandi Olaoye, said immigrants appreciate the freedom and stability the United States offers but feel the country has become too secular. He cited the restrictions on prayer in school and the move toward gay marriage.

"The foundation of this country was Christianity, and that's what made this country great," said Olaoye, who was sent by Nigerian officials to Silver Spring to lead the church.

Still, Olaoye and other clergy and religion scholars said African immigrants are unlikely to have a broad influence on U.S. society until their numbers become more significant.

When the first openly gay Episcopal bishop was consecrated in New Hampshire last month, church leaders in Africa were the most vehement in their condemnation. Many Africans in the United States felt similarly but hesitated to be so vocal.

"They are really not in a position to say much," said Emmanuel Nwokolo, who emigrated from Nigeria in 1988 and is senior warden at St. John's. "Here, it's really hard to go against the bishop. There's a fair amount of liberalism associated with living in America, and we have to accept that."

Besides, he said, there are so many other concerns at a vibrant, growing church.

In the packed fellowship hall last Sunday, a church leader auctioned off crockpots of food that raised about $6,000. In the back of the room, parishioners helped themselves at tables that groaned with pans of plantains, yams, beans, baked chicken and sweet dough snacks that celebrated a West African harvest holiday similar to American Thanksgiving.

Fourteen-year-old Maureen Ebele Obike, who emigrated with her family from Nigeria five years ago, said that she had been surprised to find so many churches with Nigerians that they could choose to attend. Sitting on a sofa, she cradled her baby brother as other children stopped to admire the infant.

"It's like being home, except there are other people here, too, more people from different ethnic groups," she said.

Brian Roman, a white parishioner who has attended St. John's since 1981, felt at home, too. Roman, 58, said that when the choir sings in Igbo, he's able to follow along because the tunes are the same hymns that he grew up with. Many times, he said, he's been impressed and inspired by African parishioners who come to the church for worship even on weekdays and can cite specific Scriptures.

"I'm impressed by their sense of seriousness," he said. "There is a dedication to understanding the Gospel and not forgetting it the rest of the week after Sunday. It makes me think I should be more familiar with it."

As Roman hurried to leave the holiday bazaar early to go to his job at Amtrak, two women wearing brightly patterned dresses and scarves insisted on fixing him a paper plate of plantains. Arthur Dixon, the church treasurer, who is originally from Sierra Leone, offered him a ride to the train station.

In a way, the gray-haired Roman was being treated like a welcomed immigrant at St. John's.