It is a rare gesture for a U.S. political leader. But what makes Mr. Obama's outreach especially remarkable is that it is accompanied by public displays of faith that sometimes go beyond even those of his religiously oriented predecessor in the White House.
The outreach toward both ends of the religious spectrum makes for a complicated balancing act, one that runs the risk of alienating one group, the other, or possibly both. . . .
But even when taking these stands, which would be expected of a Democratic president, he often makes a point to say that he understands the other side.
That stance could win him respect from both sides, but it will be difficult to pull off. "Showing respect and being inclusive will only take the president so far," said John C. Green, senior fellow at the Pew Forum on Religion and Public Life.
If Mr. Obama makes too many policy decisions that run counter to religious conservatives, Mr. Green predicted that they won't support him, no matter how much they appreciate the outreach.
At the same time, he said, nonreligious Americans could become irritated with outward expressions of religious faith.
Mr. Obama acknowledged nonbelievers on the campaign trail last year, and, notably, in his inaugural address, where he said: "We are a nation of Christians and Muslims, Jews and Hindus, and nonbelievers."
"This was...probably the first time a president in a formal inaugural address acknowledged the possibility that there could be Americans who don't believe in God," said Ed Buckner, president of American Atheists, a group with more than 3,000 members.
While nonbelievers welcomed Mr. Obama's recognition, the move could make some people uneasy. Americans are less comfortable with atheists than they are with many other minority groups, according to a 2006 University of Minnesota study. Nearly half of those surveyed said they would disapprove if their child wanted to marry an atheist, versus a third who said the same of a Muslim. People were more accepting of homosexuals, conservative Christians, immigrants, Hispanics and Jews.
A 2008 American Religious Identification Survey, conducted by Trinity College in Hartford, Conn., found that 15% of Americans are unaffiliated with any religion, up from 8.2% in 1990. In 2008, only 0.7% identified themselves as atheists and 0.9% said they are agnostic.
Bishop E.W. Jackson Sr. of Exodus Faith Ministries in Chesapeake, Va., a nondenominational church, finds Mr. Obama's acceptance of nonbelievers offensive. "I believe every American should worship however they wish," he said, "however to deny that the country is fundamentally Christian in its culture and its heritage is just not true."