The selection of New Hampshire Episcopal Bishop Gene Robinson for Sunday's event follows weeks of criticism from gay-rights groups over Obama's decision to have the Rev. Rick Warren give the invocation at his Jan. 20 inauguration. Robinson said last month the choice of Warren was like a slap in the face. In an interview with the Concord Monitor, he said he doesn't believe Obama invited him in response to the Warren criticism but said his inclusion won't go unnoticed by the gay and lesbian community.

"It's important for any minority to see themselves represented in some way," Robinson told the newspaper for a story in Monday's editions. "Whether it be a racial minority, an ethnic minority, or in our case, a sexual minority. Just seeing someone like you up front matters."

Clark Stevens, a spokesman for the inaugural committee, said Robinson was invited because he had offered his advice to Obama during the campaign and because of his church work. When asked whether Robinson was included to calm the Warren complaints, he said Robinson is "an important figure in the religious community. We are excited that he will be involved."

As for himself, Robinson said he doesn't yet know what he'll say, but he knows he won't use a Bible. "While that is a holy and sacred text to me, it is not for many Americans," Robinson said. "I will be careful not to be especially Christian in my prayer. This is a prayer for the whole nation." Robinson said his prayer will be reflective of the times.

Gay advocates assailed Obama, while many conservative Christians were heartened, when he invited the Rev. Rick Warren, a Southern Baptist who opposes gay marriage, to deliver the inaugural invocation on Tuesday. The tables turned when Obama asked V. Gene Robinson, the first openly gay Episcopal bishop, to lead prayers at Sunday's kickoff for the inauguration at the Lincoln Memorial. Gay rights groups rejoiced, while some conservative Christians wrung their hands.

A prayer will be offered at the National Cathedral by Ingrid Mattson, the first woman president of the Islamic Society of North America, according to an official who spoke on condition of anonymity because they were not authorized to release the information. The Islamic Society, based in Indiana, is the nation's largest Muslim group.

Three rabbis, representing the three major branches of American Judaism, will also say a prayer at the service, according to officials familiar with the plans. The Jewish clergy are Reform Rabbi David Saperstein, Conservative Rabbi Jerome Epstein and Orthodox Rabbi Haskel Lookstein, sources said.

It is also traditional for the incoming administration to ask the Roman Catholic archbishop of Washington to lead a prayer. The Most Rev. Donald Wuerl leads the archdiocese.

But Obama's choice of clergy is also of greater interest because of the changing landscape of American religion. The United States is more diverse than ever before, and members of minority faiths yearn to be recognized as fully American. Even atheists are newly energized, suing to prevent prayer and mention of God at the swearing-in.

"The sense is it's time to balance that out and to have other voices heard. He's supposed to represent change," Haynes said. "There are many people looking for a symbolic change in tone, especially when it comes to issues of religion and public life."

The church leaders have recognized and stressed the critical role of ecumenism, or religious unity, in peace efforts.

"I want to emphasize one point: the ecumenical movement, of which the National Council of Churches is an instrument, is most essentially a movement of peace," Kinnamon stated. "Part of the point is sociological: Christian divisions (which ecumenism seeks to overcome) often exacerbate political conflicts and hinder effective peacemaking. War is too massive an evil to be responded to denominationally."

Members of the Historic Peace Churches are calling people of faith to seek nonviolent ways to confront the violence, terrorism and fear prevailing in many countries. They are not only inviting believers from the various Christian denominations but also representatives of the Jewish and Muslim faiths to join the efforts for peace.

"We are deeply aware that the most effective work for peace will ultimately require interfaith vision, effort and cooperation," a statement from the meeting's website says.

Asking Christians to set aside their fears - fears within the peace churches that unity would weaken their peace message or fears among Christians seeking unity that a message of peacemaking would prove divisive - Kinnamon challenged believers to be "ambassadors of reconciliation by the way we live with one another."