Pope Benedict XVI is weighing in on the perennial debate about the role of religion in American politics, appearing at the White House yesterday with President Bush to cite both President Washington and the Declaration of Independence in making the case that, as the pontiff put it, “America’s quest for freedom has been guided by the conviction that the principles governing political and social life are intimately linked to a moral order based on the dominion of God the Creator.”

The pope referred to the Declaration of Independence in recalling, “The framers of this nation’s founding documents drew upon this conviction when they proclaimed the self-evident truth that all men are created equal and endowed with inalienable rights grounded in the laws of nature and of nature’s God.” And he quoted Washington’s Farewell Address in asserting that religion and morality represent “indispensable supports” of political prosperity.

The pope spoke of how religious beliefs were “a constant inspiration and driving force” in the struggle against slavery and in the civil rights movement. He did not mention that the pro-slavery forces and those who opposed civil rights also invoked religion.

Here in New York, the paint was drying on the homemade “We Love Benedict” banners, priests and television crews were working out the complicated logistics for getting parishioners and cameras into Yankee Stadium, and police officials were in last-minute meetings to ensure security is airtight as the city prepares to welcome Pope Benedict on Friday.

Almost immediately after his arrival on Friday morning at John F. Kennedy International Airport, Benedict will begin a flurry of meetings with Catholics and interfaith groups across the city that will include at least one first: the first papal visit to an American synagogue.

At the White House yesterday, in his first public presentation in America as pope, Benedict said he was looking forward to meeting not only American Catholics for the first time in his new role, but also meeting with “other Christian communities and representatives of the many religious traditions present in this country.”

In a speech addressed to thousands gathered on the White House lawn, Benedict continued: “As the nation faces the increasingly complex political and ethical issues of our time, I am confident that the American people will find in their religious beliefs a precious source of insight and an inspiration to pursue reasoned, responsible, and respectful dialogue in the effort to build a more humane and free society.”

The focus on unity and praise for America’s democracy presented itself as an early theme for this papal visit. In his speech, he also cited the words of his predecessor, John Paul II. “In a word, freedom is ever new. It is a challenge held out to each generation, and it must constantly be won over for the cause of good,” he said.

In his own speech, President Bush said he hoped the pope’s visit would be “a source of renewal and hope for the church in the United States.”

Mr. Bush, a Methodist, also seemed to allude to their similar views on abortion and stem cell research, although he didn’t address them directly: “In a world where some treat life as something to be debased and discarded, we need your message that all human life is sacred and that each of us is willed, each of us is loved, and each of us is necessary,” the president said.

The pope did not explicitly address either the Iraq War or the abortion issue in his remarks yesterday. On his flight from the Vatican, he spoke of the clergy sexual abuse scandal that has shaken the Catholic Church here in the past several years, and the topic may come up again. Immigrant groups have also hoped he’ll discuss publicly the problems with the American immigration system, an issue he has expressed concern about in the past and talked about yesterday with the president, according to a joint statement from the White House and the Holy See. The joint statement said: “The Holy Father and the President devoted considerable time in their discussions to the Middle East, in particular resolving the Israel-Palestinian conflict in line with the vision of two states living side-by-side in peace and security, their mutual support for the sovereignty and independence of Lebanon, and their common concern for the situation in Iraq and particularly the precarious state of Christian communities there and elsewhere in the region. The Holy Father and the President expressed hope for an end to violence and for a prompt and comprehensive solution to the crises which afflict the region.”

The seriousness of the pope’s and president’s messages and the highly ceremonial event was lightened somewhat by the fact that it was Benedict’s 81st birthday yesterday. The audience sang him “Happy Birthday” twice, and at least one birthday cake was spotted among the crowd. The president and first lady also offered him cake at a reception after the speeches.

There will be more birthday celebrations in New York, although the pope’s first stop in New York on Friday will be a little more sedate as he spends three hours at the United Nations meeting with the Secretary-General and other international leaders.

Afterward, at 6 p.m., Benedict, originally from Germany, will visit Saint Joseph’s Parish on the Upper East Side, founded by Germans more than a century ago. Both Protestants and Catholics will gather for the ecumenical service.

On Saturday, as many as 3,000 clergy from around the region will gather at St. Patrick’s Cathedral, where Benedict will say Mass after being escorted in by Mayor Bloomberg. Later in the day, he will meet with disabled Catholic youth and seminarians at St. Joseph’s Seminary in Yonkers for a rally. Pop star Kelly Clarkson will perform, and the pope will open birthday presents before addressing an expected crowd of 25,000.

The weekend will culminate with a motorcade down Fifth Avenue before he arrives at Yankee Stadium on Sunday to say Mass for a crowd of about 57,000.

Many of the thousands of New Yorkers who flock to see him this weekend will be immigrants, a force that has reinvigorated the Catholic Church in recent years. At Our Lady of Mount Carmel in East Harlem, Father Anthony Kelly said a group of about 16 of the church’s youngest members, almost all of them immigrants from Mexico, were preparing to travel to the Yonkers rally on Saturday with painted signs to wave. Father Kelly said they would probably bring along Mexican flags to wave as well.

“They’re getting very excited,” he said.