The Rev. Rob Schenck is an evangelical Christian and a leader of the religious right. Rabbi David Saperstein is a Reform Jew and a leader of the religious left. Both head political advocacy groups in Washington, and they have battled for years over abortion, gay rights, stem cell research and school prayer.

This summer, each intends to preach a bit of the other's usual message.

Schenck said he plans to tell young evangelicals at a Christian music festival on July 1 that homosexuality is not a choice but a "predisposition," something "deeply rooted" in many people. "That may not sound shocking to you, but it will be shocking to my audience," he said.

Saperstein said he is circulating a paper urging political moderates and liberals to "demonstrate their commitment to reduce abortions" by starting a campaign to reduce the number by half within two years.

Schenck and Saperstein disclosed their plans in separate interviews. They are not working together. The minister remains a die-hard opponent of same-sex marriage; the rabbi staunchly supports a woman's constitutional right to choose an abortion. But both are trying to find common ground between liberals and conservatives on moral issues -- and they are not alone.

After a year in which religion played a polarizing role in U.S. politics, many religious leaders are eager to demonstrate that faith can be a uniter, not just a divider. The buzzwords today in pulpits and seminaries are crossover, convergence, common cause and shared values.

Last week in Washington, representatives of more than 40 U.S. denominations took part in the Convocation on Hunger at the National Cathedral, where they sang a Tanzanian hymn while the choir director shook a gourd full of seeds and children laid breads from around the world on the altar.

It may have been mistaken for a hippie ceremony were it not for the sight of clergy from the Southern Baptist Convention, Assemblies of God and other evangelical churches praying alongside Muslims, Buddhists, Sikhs, Roman Catholics, Greek Orthodox, mainline Protestants and Jews.

The show of solidarity was partly a reaction against "the recent manipulation of religion in ways that are divisive and partisan," said David Beckmann, a Lutheran minister and president of Bread for the World, a nonprofit group that helped organize the service.

"Because religion has been dragged into political life in some ways, this is the religious leadership of the nation saying, 'No, let us show you what religion in the public square should really be about,' " he said.

Meanwhile, the United Methodist Church, Episcopal Church and Evangelical Lutheran Church in America are moving quickly toward full communion, which would allow them to swap clergy and recognize one another's sacraments. Protestant and Jewish leaders, who have been at loggerheads over proposals to divest stock in companies that help Israel maintain control of the Palestinian territories, have announced a joint trip to the Holy Land in September.

The National Association of Evangelicals is promoting dialogue with Muslims, concern for the environment and efforts to combat poverty. "On issues like poverty, the cold war among religious groups is over," said the Rev. Richard Cizik, its vice president for public policy.

The Rev. Don Argue, a past president of the NAE, is an informal adviser to Sen. Hillary Rodham Clinton (D-N.Y.), who has introduced legislation aimed at reducing the demand for abortions without restricting their availability. Jim Wallis, a left-leaning evangelical whose bestselling book "God's Politics" is a plea for liberals and conservatives to identify common causes, has worked with the staff of Sen. Rick Santorum (R-Pa.), as well as with Democrats on antipoverty proposals.

Some observers view all this aisle-crossing mainly as political positioning.

"There's a kind of pulling back from religious war," said Mark R. Silk, director of the Center for the Study of Religion in Public Life at Trinity College in Hartford, Conn. "But I don't think one should overlook the self-interest of both sides, at this moment, in positioning themselves as willing to compromise and work with the other side."

In last year's presidential election, voters who said they attend church more than once a week favored President Bush over Sen. John F. Kerry (D-Mass.) by a ratio of nearly 2 to 1. White evangelicals backed Bush by almost 4 to 1. Occasional (less than weekly) churchgoers tilted narrowly toward Kerry, and secular voters overwhelmingly favored the Democrat, according to exit polls.

Religion was not just a defining issue in the campaign but a divisive one. Some Catholics questioned Kerry's worthiness to receive Holy Communion because of his stand on abortion rights. Church-based activists pushed referendums on same-sex marriage onto 13 state ballots.

Since the election, Democrats on Capitol Hill have tried to demonstrate that their positions are infused by faith; Republicans have sought to show that their moral concerns go beyond abortion and same-sex marriage.

"On the left, they need to show they have a religious bone in their body. On the right, they have to prove their vaunted values are not limited to one or two hot-button issues," Silk said. "So count me a little skeptical about how far this 'crossover' and 'convergence' really goes."

Saperstein, who heads the Religious Action Center, the Washington advocacy arm of the Reform movement in Judaism, said he believes the search for common ground is "both strategic and substantive."

"I think it's genuine and real, this engagement of liberals in trying to cut the number of abortions in this country," he said. "And I think conservatives are sincere when they say, 'I may be against gay marriage, but the demonization of gays and lesbians is deeply troubling to me,' or when they say, 'You can't look at the Bible without seeing the call to care for the poor.' "

Saperstein noted that the phenomenon of strange bedfellows began a decade ago on foreign policy. During the Clinton administration, the rock star Bono, former senator Jesse Helms (R-N.C.) and religious leaders across the political spectrum teamed up to champion debt relief for Africa. Since Bush took office, broad religious coalitions have backed U.S. peacemaking efforts in Sudan, funding to combat AIDS and pressure on countries that restrict religious freedom.

What is new, the rabbi said, is the effort to forge such coalitions on domestic issues.

"For 25 years, evangelicals involved in conservative politics and mainline denominations involved in liberal politics really have been adversaries, both in politics and in the free market of ideas, and that continues because we have very different visions of religion in American public life, and very different views of the Constitution, and very different views on some core issues," he said.

"But right now on abortion, poverty, gay issues, the environment, there's a lot of talk about crossing the lines and finding common ground. There are elements of a common vision, but not yet common policy or legislative proposals."

Schenck, who is president of Faith and Action, an evangelical organization on Capitol Hill, said that a willingness to reach across partisan lines is attractive, particularly to young people. "I think evangelicals are awakening to the vulnerability to being used in a political way. I hear a lot of people talking about that, about not being owned by a political party," he said.

Schenck outlined his limits: "There is no room for compromise on the sanctity of human life, the sanctity of marriage and the public acknowledgement of God." But he said that when he preaches at the Creation Festival, a four-day Christian music event in Mount Union, Pa., he will say that the Bible forbids homosexual acts but that evangelicals are wrong to insist that sexual orientation is a matter of choice.

"As far as affirming that there may be people in our midst who have this as their nature, that will be radical within evangelical circles, because we want to see this purely as an act of will, like breaking and entering," he said. "And it just isn't that. It is so much more complex. If young people hear Christian leaders like me say that, I think they'll be interested in hearing what more we have to say."

The Rev. Rob Schenck says a willingness to reach across partisan lines is attractive, especially to young people.Rabbi David Saperstein says he believes the search for common ground is "both strategic and substantive."