WASHINGTON — The United Church of Christ wants to rev up a hip television advertising campaign that welcomes gays and others who feel out of place elsewhere, but the move is alienating some of the progressive denomination's members.

About 6,000 United Church of Christ congregations have 1.3 million members in the United States. Between 80 and 100 congregations could break from the fold because of the "God is Still Speaking" advertising campaign and the July decision by the denomination's ruling body to endorse same-sex marriage, said David Runnion-Bareford, executive director of the Biblical Witness Fellowship in New Hampshire.

Runnion-Bareford's group represents more conservative United Church of Christ congregations. Some of them say the campaign is attracting heterosexuals and homosexuals who have sex outside of marriage, which is against biblical teachings, Runnion-Bareford said.

"There are all kinds of different voices speaking up, raising questions" about the ads, he said.

The ads show beefy bouncers blocking so-called undesirables, including a gay couple and nonwhites, from worshipping. A voiceover says the United Church of Christ welcomes you no matter who you are.

Mark Henderson and Charles Dowdy, a black gay couple with two children, joined St. Luke's United Church of Christ in Philadelphia last spring. One of Dowdy's co-workers and his wife saw the ad, visited the church and suggested it would be a good fit for the couple.

Henderson, 41, and Dowdy, 40, said they have been fully accepted. "I'll put it to you this way: We're a gay couple with two children that we adopted," Henderson said. "To go there and not have people look at you as crazy was very important to us."

But seven months after the ad began airing, the 126 members of the First Congregational Church in Torrington, Conn., voted to leave the United Church of Christ umbrella, pastor Steve Darr said.

The church welcomes all visitors but follows the traditional biblical interpretation of homosexuality being a sin, Darr said. The congregation had additional reasons for the split, he said, including the denomination's abortion-rights stance. "There were some questions about where they were going," Darr said of the United Church of Christ.

The advertising seeks to attract the almost 60 percent of Americans who do not attend church regularly, said Ron Buford, coordinator of the "God is Still Speaking" campaign.

About four in 10 congregations are taking part and agreed to accept anyone who wanted to join, he said.

The ads have been in play since December, and the church plans a new ad blitz in the spring — just in time for Easter.

Visits to United Church of Christ Web sites quadrupled after the ads first aired, and some participating congregations are reporting membership increases, Buford said.

The Plymouth Congregational Church-United Church of Christ in Des Moines had 41 people in its new-member class a few weeks ago, the highest number in six years, partly due to the ads, the Rev. David Ruhe said.

The United Church of Christ is the 21st largest Christian denomination in the United States, according the National Council of Churches USA. Catholics are the largest denomination, with more than 67 million members.

Older, mainline denominations such as the United Church of Christ need to attract new members because they have lost ground to a rising modern evangelical church movement, said Kenneth Rose, associate professor of religious studies at Christopher Newport University in Virginia. Evangelical churches tend to be more conservative.

The issues of same-sex marriage and acceptance of gay members and clergymen are dividing other Christian denominations, including the United Methodist Church and Anglican Church. But one expert said others should follow the United Church of Christ's example.

"I applaud (the United Church of Christ) for what they are doing," said Cheryl Giles, a professor of pastoral care and counseling at Harvard Divinity School. "Many of the churches focus much too much on making judgment on people rather than creating opportunities for people to express their own religious beliefs and spirituality."