HUNTINGTON, W.Va.(AP) — Greg Mencotti worried he would never find a spiritual home.
The Sunday school teacher grew up Roman Catholic, lost his faith and became an atheist. Eventually, he returned to Christianity, this time as a born-again Christian, spending years worshipping in a Methodist congregation. Still, he felt his search wasn't over.

That led him to the Holy Spirit Antiochian Orthodox Church in Huntington, W. Va., a denomination with Mideast roots that, like all Orthodox groups, traces its origins to the earliest days of Christianity.

Today, Mencotti is one of about 250 million Orthodox believers worldwide — and among a significant number of newcomers attracted to this ancient way of worship. The trend is especially notable since so few in the United States know about the Orthodox churches here.

"I was like most Americans," said Mencotti, who was urged by his wife to explore Orthodox worship. "I didn't understand anything about Orthodoxy."

Orthodoxy was born from the Great Schism of 1054, when feuds over papal authority and differences in the liturgy split Christianity into Roman Catholic and Eastern Orthodox halves.

In the United States, Orthodox Christians are a fraction of religious believers, numbering about 1.2 million, according to estimates by Orthodox researchers.

In the past, their growth had been largely fueled by immigration, with churches forming mainly along ethnic lines. Some converts came to Orthodoxy through marriage to a church member.

But now about one-third of all U.S. Orthodox priests are converts — and that number is likely to grow, according to Alexei D. Krindatch, research director at the Patriarch Athenagoras Orthodox Institute in Berkeley, Calif. A 2006 survey of the four Orthodox seminaries in the country found that about 43% of seminarians are converts, Krindatch said.

There are no exact figures on the rate of conversion across the 22 separate U.S. Orthodox jurisdictions. But when Mencotti began attending Orthodox worship, the church was packed with converts, including the church's pastor, the Rev. John Dixon.

The Rev. John Matusiak, pastor of St. Joseph Church in Wheaton, Ill., part of the Orthodox Church in America, said his parish has grown from 20 people in the early 1990s to more than 600 today, with the overwhelming majority of new members younger than 40.

Krindatch's research found that one-third of the more than 200 U.S. parishes in the Antiochian Orthodox Church were founded after 1990.

Matusiak said growth is especially apparent in suburbs and commuter towns. "People in Wheaton weren't flocking to Orthodoxy, because there was never a church here," Matusiak said.

Many converts credit the beauty of the liturgy and the durability of the theology, which can be a comfort to those seeking shelter from divisive battles over biblical interpretation in other Christian traditions.

Dixon, who was raised an Old Regular Baptist, an austere faith of the Southern Appalachians, said his conversion grew from his studies about the origins of Christianity as an undergraduate at Marshall University. The turning point came when he first attended services at an Orthodox church.

"As soon as I came in that day," he says, "I knew I was home."

Convert-fueled growth, though, has its challenges.

Like converts in all faiths, the newly Orthodox bring a zeal that can be unsettling for those born into the church, who tend to be more easygoing in their religious observance. Parishes run the risk of dividing between new and lifelong parishioners, Krindatch says.

"Converts to Orthodoxy form their own little quasi-seminary and it's almost a closed group," says the Rev. Joseph Huneycutt, associate pastor of St. George Anti-ochian Orthodox Church in Houston, who was raised Southern Baptist then became Orthodox.

And some worry about converts' impact on the churches. They are entering the parishes at a time when many lay activists across Orthodox denominations are pushing church leaders to let go of ethnic divisions and pool resources so they can better evangelize in the United States.

Huneycutt, author of One Flew Over the Onion Dome, a book about conversion, and the editor of OrthoDixie, a blog about Orthodoxy in the South, said he was drawn to the faith by the beauty of its rituals and its teachings.

On his first visit, he said the church was filled with the smell of incense and the sound of the chanted Divine Liturgy. The altar was largely concealed by the iconostasis, a large screen or wall hung with icons of Christ, Mary, angels and Apostles. And worshippers received Communion from a chalice and spoon.

"I had become convinced that the Eucharist was the center of Christian worship — ancient Christian worship," Huneycutt says. "Once I had reached that point in my personal walk with Christ, there was no going back."