He's done it while talking about abortion and the Middle East, even the economy. The references serve at once as an affirmation of his faith and a rebuke against a rumor that persists for some to this day.
As president, Barack Obama has mentioned Jesus Christ in a number of high-profile public speeches - something his predecessor George W. Bush rarely did in such settings, even though Bush's Christian faith was at the core of his political identity.
In his speech Thursday in Cairo, Obama told the crowd that he is a Christian and mentioned the Islamic story of Isra, in which Moses, Jesus and Mohammed joined in prayer.
At the University of Notre Dame on May 17, Obama talked about the good works he'd seen done by Christian community groups in Chicago. "I found myself drawn - not just to work with the church but to be in the church," Obama said. "It was through this service that I was brought to Christ."
And a month before that, Obama mentioned Jesus' Sermon on the Mount at Georgetown University to make the case for his economic policies. Obama retold the story of two men, one who built his house on a pile of sand and the other who built his on a rock: "We cannot rebuild this economy on the same pile of sand," Obama said. "We must build our house upon a rock."
More than four months into the Obama presidency, a picture is emerging of a chief executive who is comfortable with public displays of his religion - although he has also paid tribute to other faiths and those he called "nonbelievers" during his inaugural address.
Obama's invocation of the Christian Messiah is more overt than Americans heard in the public rhetoric of Bush in his time in the White House - even though Bush's victories were powered in part by evangelical voters.
"I don't recall a single example of Bush as president ever saying, ‘Jesus' or ‘Christ,'" said Tony Perkins, president of the conservative Christian group Family Research Council. "This is different."
To Perkins, Obama's overtly Christian rhetoric is a welcome development from an administration that he largely disagrees with on the issues, though Perkins sees a political motive behind it, as well.
"I applaud that. It gives people a sense of comfort," Perkins said. "But I think it's a veneer, a facade that covers over a lot of policies that are anti-Christian." That includes, in his view, Obama's stance in favor of abortion rights.
The Rev. Barry Lynn, the executive director of the group Americans United for Separation of Church and State, doesn't like the trend with Obama: "I don't need to hear politicians tell me how religious they are," Lynn said. "Obama in a very overt way does what Bush tended to do in a more covert way."
Obama's public embrace of his Christianity so far has not included choosing a church in the capital, and he has attended Sunday services only once since his election, on Easter Sunday. The White House said at the time the family was still looking for a spiritual home in Washington.
But inside his White House, Obama has placed his Office of Faith-Based and Neighborhood Partnerships - run by a 26-year old Pentecostal minister named Josh DuBois - under the White House's Domestic Policy Council. That was widely seen as an effort to involve a religious perspective in the administration's policy decisions.
Also, religious leaders meet with White House policymakers on a regular basis - and help to shape decisions on matters large and small. A White House speechwriter working on Obama's Egypt speech called several faith leaders to get their thoughts. After the White House unveiled its budget in April, officials convened a two-hour conference call with religious leaders to discuss how the spending plan would help the poor.
"President Obama is a committed Christian, and he's being true to who he is," DuBois told POLITICO. "There's an appropriate role for faith in public life, and his remarks reflect that. And they also reflect a spirit of inclusivity that recognizes that we are a nation with a range of different religious backgrounds and traditions."
Still, it is ironic that Obama, who rode a wave of young, Internet-savvy and more secular voters to the White House, would more freely invoke the name of Jesus Christ than did Bush.
In his first year as president, Bush mentioned "Jesus" or "Christ" a handful of times - but only in innocuous contexts, such as his Easter proclamation, a Christmas message and a proclamation on "Salvation Army Week."
To be sure, Bush talked openly about his faith. On the day of his second inauguration as governor of Texas, Bush reportedly told Richard Land of the Southern Baptist Convention, "I believe that God wants me to be president." As a Texas governor running for president, Bush declared in a presidential debate that the philosopher he most identified with was Jesus.
And in an interview for Bob Woodward's 2004 book "Plan of Attack," Bush was asked whether he'd talked to his father, the President George H.W. Bush, about the decision to invade Iraq.
"There is a higher father that I appeal to," Bush said.
But there are different political imperatives driving the two presidents. Obama has every incentive to broadcast his Christianity, while Bush, for other reasons, chose to narrowcast his religious references to a targeted audience.
For Obama, Christian rhetoric offers an opportunity to connect with a broader base of supporters in a nation in which 83 percent of Americans believe in God. What's more, regularly invoking Jesus helps Obama minimize the number of American who believe he is a Muslim - a linkage that can be politically damaging. According to a Pew Research Center study, 11 percent of Americans believe, incorrectly, that Obama is a Muslim; it's a number that is virtually unchanged from the 2008 presidential campaign.
Yet Obama has targeted his messages, too. He used speeches in Turkey and last week in Egypt to highlight the Muslim relatives in his past as a way to draw a connection with his Muslim audiences - something he shied away from during his presidential campaign.
For Bush, invoking Jesus publicly was fraught with political risk. He was so closely politically identified with the Christian right that overt talk of Christ from the White House risked alienating mainstream and secular voters. Bush instead quoted passages from scripture or Christian hymns, as he did in his 2003 State of the Union Address when he used the phrase "wonder-working power." That sort of oblique reference resonated deeply with evangelical Christians but sailed largely unnoticed past secular voters.
To some, the difference between the two presidents goes beyond rhetoric. David Kuo, a former official in Bush's faith-based office who later became disillusioned with the president he served, worries that both men have exploited religious phraseology for political gain. "From a spiritual perspective, that's a great and grave danger," he said. "When God becomes identified with a political agenda, God gets screwed."
And he suspects that Obama has an even larger goal: the resurrection of the largely dormant Christian Left, a tradition that encompasses Martin Luther King's civil rights leadership and dates back as far as Dorothy Day, the liberal activist who co-founded the Catholic Worker movement in the 1930s.
Recast in 21st Century terms, that long-dormant stream of American political life could become a powerful political force. A Pew survey released May 21 found that even as Americans remain highly religious, there has there been a slow decline in the number of Americans with socially conservative values - especially among young voters. That creates an opening for Obama, especially at a time when some conservative evangelicals are telling pollsters they are frustrated and disillusioned with politics.
"In the long term, this could be huge," said Stephen Schneck, director of the Life Cycle Institute at The Catholic University of America, who is active in left-leaning political efforts. "There are swing Catholics and swing Protestants even within the evangelicals. To the extent Obama can mobilize those people as part of a new Democratic coalition, that marginalizes Republicans even further."