The latest addition to the liberal United Church of Christ is a gay-friendly megachurch: the Cathedral of Hope. It's the most recent major move for the mainline Protestant denomination in declaring its full acceptance of gay and lesbian relationships.

"The UCC is clearly going after a certain niche in American society who are very liberal and have a particular religious vision that includes inclusiveness," said John Evans, associate professor of sociology at the University of California, San Diego. "They are becoming the religious brand that is known for this."

The Cathedral of Hope in Dallas, which claims 4,300 members, was admitted to the Protestant group Oct. 28 on a 32-9 vote of the United Church's North Texas Association. The megachurch is now the fourth-largest congregation in the 1.3 million-member denomination.

The cathedral describes itself as "the world's largest liberal Christian church with a primary outreach to lesbian, gay, bisexual and transgender people." That outlook fits with the beliefs of the United Church of Christ, which last year endorsed gay marriage — becoming the largest Christian denomination to do so.

"They are a progressive denomination, and they have taken progressive stands all along," said the Rev. Michael S. Piazza, the cathedral's national pastor and dean. "When they took that vote, it really made it clear that was our home."

In the early 1970s, UCC became the first major Christian church to ordain an openly gay minister. Soon after, the church declared itself "open and affirming" of gays and lesbians. Church members then voted overwhelmingly to back same-sex marriage in a July 2005 national assembly.

Many mainline Protestant denominations are divided over how to interpret Bible passages about sexuality. Christians with traditional views contend that Scripture bars gay relationships, while supporters of ordaining gays believe the Bible's social justice teachings on inclusiveness should prevail.

Piazza said the United Church of Christ is "on the right side of history." But the long-term impact of the denomination's liberal approach is unclear, Evans said.

About 140 churches in the 5,700-church denomination left the United Church of Christ since the denomination endorsed gay marriage, said the Rev. Bennett Guess, UCC spokesman. The Puerto Rico conference of the denomination, which has about 60 churches, also has decided to break away, though some individual churches may stay, he said.

But Guess said 65 churches have expressed interest in joining the denomination in the past year or so, the most since UCC was formed in 1957 by the union of the Congregational Christian Churches in America and the Evangelical and Reformed Church. The Protestant denomination also seems to be making some inroads as an alternative in the South, where conservative evangelical churches dominate. Four years ago, the 5,500-member Victory Church in Stone Mountain, Ga., became the UCC's second-largest church.

Before the Dallas cathedral's application was approved by the United Church of Christ, the denomination had only 13,648 members and 85 churches in Texas and Louisiana. Eighty percent of the Protestant church's members live in the Northeast or industrial Midwest.

"I hope that we help initiate a dialogue about what it means to be a vitally alive, vibrant congregation in terms of worship and vision," said the Rev. Jo Hudson, senior pastor of the cathedral. "I think that's a direction the UCC is seeking to go."

The cathedral separated in 2003 from the Universal Fellowship of Metropolitan Community Churches, which had been formed to give full inclusion to gays and lesbians, after a dispute over Piazza's financial management. The congregation voted a year ago to seek affiliation with the United Church of Christ, although ties with the denomination go back further.

Piazza said a 1997 congregational vote authorized exploration of denominational affiliation with the UCC. But the potential union met obstacles, including a resolution preventing the North Texas association from "knowingly" ordaining gay or lesbian ministers. The resolution has since been repealed.

John Vigus of the UCC's North Texas Association contends the recent vote demonstrated growing acceptance of gays and lesbians. More people are thinking, " 'Maybe that was wrong,' " Vigus said, about condemnation of same-sex relationships. " 'We've been doing it in the past, but maybe we were wrong.' "