It's a voice that signals openness at a time when diversity in American religious life is rising.
"We know that our patchwork heritage is a strength, not a weakness. We are a nation of Christians and Muslims, Jews and Hindus – and nonbelievers," Mr. Obama said in Tuesday's inaugural address.
Wednesday's National Prayer Service, a tradition since George Washington's inauguration, featured faith leaders chosen "to symbolize America's traditions of religious tolerance and freedom," said the 2009 Presidential Inaugural Committee. It included, for the first time, a sermon delivered by a woman.
For Obama, the broad outreach into the faith community isn't confined to ceremonies but is emerging as a key element in his approach to coalition-building, say religious leaders who worked on the transition.
"Barack Obama is himself a person of faith, but he also believes that the faith community has a real role to play in creating the kind of social change we need now," says the Rev. Jim Wallis, president of Sojourners, a network of Christian social activists.
Indeed, religious groups have been broadly advising the Obama transition team on issues ranging from poverty to criminal justice to foreign policy. "To move from a consuming, polluting, poverty-creating economy to one that conserves, is a good steward of the environment, and focuses on bringing people out of poverty, that's more than a structural crisis, it's a spiritual one," says Mr. Wallis.
Obama's predisposition to stake a big tent that includes a broad range of faith traditions has been evident early.
Who leads the prayers at presidential inaugurations is usually about as controversial as whether to put an American flag near the podium. Preachers such as Billy Graham typically struck a broad, ecumenical tone acceptable to a wide range of religious adherents.
Not so this inaugural cycle. Obama's choice of the Rev. Rick Warren – a popular Evangelical who has campaigned against gay marriage – to deliver the inaugural invocation riled many liberals. Obama's subsequent invitation to V. Gene Robinson, the first openly gay Episcopal bishop, fired up the other end of the religious spectrum.
"Bless this nation with anger: anger at discrimination at home and abroad, against refugees and immigrants, women, people of color, gay, lesbian, bisexual, and transgender people," said the Right Rev. Robinson at Sunday's opening of inaugural ceremonies.
Obama's choice of two spiritual leaders with such distinct and controversial views signals that differences are not to be avoided but are an essential part of the conversation.
"Rick Warren and Gene Robinson are symbols and represent large constituencies – and were in that sense daring choices," says Charles Haynes, a scholar at the First Amendment Center in Washington. "But I think the mood of the country is to say: This is what we want. People want to see the president trying to represent the country as a whole. If there ever was a moment when we have to have a cease-fire in the cultural wars, it's now. Given the nature of the problem the country faces, we cannot afford to demonize each other, to tear each other down."
Many presidents have tried to build coalitions, including those involving religious leaders, but Obama is working from an exceptionally inclusive template.
"President Obama, like most presidents, is a coalition-builder, but this president sees a broader end product," says John Green, senior fellow at the Pew Forum on Religion and Public Life. "Obama seems to have a more inclusive view of religion than some people on the right and some people on the left.
"This is a very productive place to be but a very difficult place to be in a pluralistic society," he continues. "It is often difficult to recognize the authentic spirituality of different faiths without bringing them into conflict with each other."
At the same time, boosting religion's prominence in Democratic Party politics could deepen rifts within the party establishment.
"In religion, as in politics, he's trying to include a lot of people, and a lot of people will be upset," says Stephen Prothero, a religion professor at Boston University. "The movements for civil rights, for abolition and temperance, were movements that had religious people behind them, who were there for religious reasons. It makes sense, especially for someone like Obama for whom ideas matter so much. But there's a possibility that Democrats are going to end up being more religious than Republicans."
That prospect alarms activists who work to preserve separation of church and state.
"It remains to be seen what Barack Obama will do with the moral or ethical advice he is getting from religious leaders," says the Rev. Barry Lynn, executive director of Americans United, in Washington. "It would be odd if he were not meeting with people of faith, but he has to temper his religious views with the demands of the Constitution."
These days, at least in America, religious leaders are not the political leaders. But at the National Prayer Service here on Wednesday, Sharon Watkins, general minister and president, Disciples of Christ, noted scriptural advice to kings and leaders of yore:
"We need [the leaders of this nation] to be guided by the counsel that Isaiah gave so long ago: to work for the common good, the public happiness, the well-being of the nation and the world, knowing that our individual well-being depends on a world where liberty and justice prevailed. This is the biblical way. It is also the American way."