Parishioners say it happens quietly, unobtrusively: As the sick make their way to the altar, some worshipers begin speaking in tongues. Occasionally, one is "arrested in the spirit," falling unconscious into the arms of a fellow congregant.

The special faith-healing services, held one Sunday night a month at The Falls Church in Fairfax, are a rarity in the Episcopal Church. But members of The Falls Church have long felt at odds with fellow Episcopalians, who they believe have been drifting theologically in an ever more liberal direction.

Shortly before Christmas, The Falls Church and neighboring Truro Church -- which in Colonial times belonged to a single parish -- vented those feelings by voting overwhelmingly to break away from the 2.3 million-member Episcopal Church.

The vote reverberated across the country because Truro and The Falls Church are two of the Washington area's most wealthy, historic and prestigious congregations. Their pews are studded on Sunday mornings with such regulars as Attorney General Alberto R. Gonzales and former CIA director Porter J. Goss.

Moreover, they are reversing the usual relationship between Christians in the United States and the developing world by joining seven other Northern Virginia congregations in a new missionary branch of the Anglican province of Nigeria.

The decision was emotionally wrenching and fraught with legal issues, not least of which is a potential battle with the Episcopal Diocese of Virginia for control of the two congregations' land and buildings, conservatively valued at $25 million.

But the votes appear less sudden or surprising when one realizes that for more than 30 years, Truro and The Falls Church have been part of a "charismatic revival" within mainline Protestantism, said the Rev. Robert W. Prichard, professor of Christianity in America at the Virginia Theological Seminary in Alexandria.

Charismatic, in this case, refers to an ecstatic style of worship that includes speaking in tongues, a stream of unintelligible syllables signifying that the Holy Spirit has entered the worshiper. It is a hallmark of the fast-growing Pentecostal movement but unusual for Episcopalians, who are so thoroughly associated with solemnity and tradition that they are sometimes referred to teasingly as "the frozen chosen."

Prichard, who grew up attending Truro, said many of its members and almost of all its lay leaders spoke in tongues in the 1970s. "There was a kind of coaching in which people who had spoken in tongues would surround a person who was praying for the gift of tongues," he said.

Parishioners say the practice continues today in both congregations, though not at Sunday morning services. Some members have never seen it.

"It's very much a part of our experience and lives," said Truro Rector Martyn Minns, a new bishop in the Nigerian Anglican Church. But "we've grown up. We integrate it rather than focus on it."

Dean Miller, pastor of the young adult ministry at The Falls Church, said some members also have "visions of the Lord" during healing services. "I don't. I'm not gifted that way. But there are people in the community who do," he said.

Prichard contends that charismatic worship is vital to understanding these congregations because it paved the way for them to join the broader evangelical movement, which emphasizes being "born again," having a personal relationship with Jesus and reading the Bible as the wholly true word of God.

Unlike many Episcopal churches nationally, neither Truro nor The Falls Church was active in supporting the civil rights movement or in protesting the Vietnam War.

"I don't remember any political sermons at all," said Al Long, 80, who has been a member of The Falls Church since 1959. "We go there to find out what the Bible says and how we're supposed to live and relate to each other and the Lord. . . . And that's it."

Beginning in the 1970s, though, Truro embraced the antiabortion movement. It also started a program to help those who wanted to leave what it calls the "homosexual lifestyle."

"These emphases have never been mainstream within the Episcopal Church," said Joan Gunderson, a Pittsburgh scholar who is writing a history of the Virginia Diocese. "But there is a movement they are tapping into that is larger than just the Episcopal Church."

As Truro and The Falls Church adopted a conservative approach, dissenting members retreated to more liberal Episcopal churches in the area, such as Christ Church Alexandria. New worshipers, many of them born-again Christians who had grown disillusioned with their denominations, streamed in.

At Truro, "we don't have to water down the Gospel," said Mary Springmann, a member of the vestry and a born-again Christian who was raised Catholic.

These days, Truro is a magnet for conservatives across the Washington area, and the percentage of "cradle" Episcopalians among its 2,o00 regular worshipers has dropped steadily. In the 1980s, more than two-thirds of its members had been raised Episcopalian, according to church surveys. Today, fewer than 40 percent grew up in the church.

Truro's red brick campus sprawls over four leafy acres at the intersection of two of Fairfax City's busiest arteries. In the vaulted main sanctuary, the church embodies the centuries-old traditions of its Anglican heritage -- stately rows of candles, organ pipes set into the wall behind an ornate crucifix and wooden pews equipped with fold-down kneelers.

In the labyrinthine hallways, shelves of books reflect the church's conservative bent: advice on evangelizing to "unbelievers" and "liberal secularists," how to "engage the culture with absolute Biblical truth" and tracts against the "occultism" of the New Age movement.

The Falls Church, whose historic sanctuary dates from 1769, draws almost 2,500 worshipers to its services on an average weekend.

Goss has attended with his family for years. He said he draws spiritual sustenance from the church's strong emphasis on the teachings of Jesus. "It's a congregation that really exhibits the love of Christ," he said last week. He declined to comment on the current controversy.

At least two-thirds of the worshipers are Methodists, Presbyterians or Baptists, and there is no pressure on them to be confirmed as Episcopalians, said the Rev. Rick Wright, associate rector.

Wright said the diverse membership of both congregations illustrates one of the great changes in American religion of the past half-century: The divisions between denominations are far less important today than the divisions within denominations.

"I tend to feel very comfortable rubbing shoulders with folks at McLean Bible or Columbia Baptist . . . that are real orthodox, evangelical, biblical churches," said Truro's chief warden, or lay leader, Jim Oakes, referring to two Northern Virginia megachurches. "We share core beliefs. I think I would be more comfortable with them than with anyone I might run into at an Episcopal Diocesan Council meeting."

In some popular services, Truro and The Falls Church blend the traditional liturgy of the Book of Common Prayer with such megachurch touches as huge choirs, bass guitars and drums. Neither offers "smells and bells," the incense and chimes favored by "high church" Episcopal congregations. But some parishioners affectionately describe Truro as "McLean Bible with candles."

Attitudes toward homosexuality are one of the brightest lines between the liberal and conservative camps. But few members of Truro or The Falls Church say the division is, fundamentally, about whether to bless sex-same couples or whether to ordain gay ministers -- the issues that have strained relations between the Episcopal Church and the rest of the 75 million-member Anglican Communion, the worldwide family of churches descended from the Church of England.

Many say the rift involves something deeper -- whether the Bible is the word of God, Jesus is the only way to heaven and tolerance is more important than truth. When he was a newly ordained priest almost 20 years ago, Wright said, he talked with several other priests about how to respond to a teenager who asked, "Do you really believe in the Resurrection of Jesus?"

"The rest of the priests agreed that it was a sticky question, and they felt that way because they didn't believe in it, but they didn't want to say so," he said. "That's where the Episcopal Church has been for the last 20 years. It's not where we are."