Not everyone in the Cairo lecture hall last February was buying the imam Feisal Abdul Rauf’s message. As he talked of reconciliation between America and Middle Eastern Muslims — his voice soft, almost New Agey — some questioners were so suspicious that he felt the need to declare that he was not an American agent.

Muslims need to understand and soothe Americans who fear them, the imam said; they should be conciliatory, not judgmental, toward the West and Israel.

But one young Egyptian asked: Wasn’t the United States financing the speaking tour that had brought the imam to Cairo because his message conveniently echoed United States interests?

“I’m not an agent from any government, even if some of you may not believe it,” the imam replied. “I’m not. I’m a peacemaker.”

That talk, recorded on video six months ago, was part of what now might be called Mr. Abdul Rauf’s prior life, before he became the center of an uproar over his proposal for a Muslim community center two blocks from the World Trade Center. He watched his father, an Egyptian Muslim scholar, pioneer interfaith dialogue in 1960s New York; led a mystical Sufi mosque in Lower Manhattan; and, after the Sept. 11 attacks, became a spokesman for the notion that being American and Muslim is no contradiction — and that a truly American brand of Islam could modernize and moderate the faith worldwide.

In recent weeks, Mr. Abdul Rauf has barely been heard from as a national political debate explodes over his dream project, including, somewhere in its planned 15 stories, a mosque. Opponents have called his project an act of insensitivity, even a monument to terrorism.

In his absence — he is now on another Middle East speaking tour sponsored by the State Department — a host of allegations have been floated: that he supports terrorism; that his father, who worked at the behest of the Egyptian government, was a militant; that his publicly expressed views mask stealth extremism. Some charges, the available record suggests, are unsupported. Some are simplifications of his ideas. In any case, calling him a jihadist appears even less credible than calling him a United States agent.

Growing Up in America

Mr. Abdul Rauf, 61, grew up in multiple worlds. He was raised in a conservative religious home but arrived in America as a teenager in the turbulent 1960s; his father came to New York and later Washington to run growing Islamic centers. His parents were taken hostage not once, but twice, by American Muslim splinter groups. He attended Columbia University, where, during the Six-Day War in 1967 between Israel and Arab states like Egypt, he talked daily with a Jewish classmate, each seeking to understand the other’s perspective.

He consistently denounces violence. Some of his views on the interplay between terrorism and American foreign policy — or his search for commonalities between Islamic law and this country’s Constitution — have proved jarring to some American ears, but still place him as pro-American within the Muslim world. He devotes himself to befriending Christians and Jews — so much, some Muslim Americans say, that he has lost touch with their own concerns.

“To stereotype him as an extremist is just nuts,” said the Very Rev. James P. Morton, the longtime dean of the Church of St. John the Divine, in Manhattan, who has known the family for decades.

Since 9/11, Mr. Abdul Rauf, like almost any Muslim leader with a public profile, has had to navigate the fraught path between those suspicious of Muslims and eager to brand them as violent or disloyal and a Muslim constituency that believes itself more than ever in need of forceful leaders.

One critique of the imam, said Omid Safi, a professor of religious studies at the University of North Carolina, was that he had not been outspoken enough on issues “near and dear to many Muslims,” like United States policy on Israel and treatment of Muslims after 9/11, “because of the need that he has had — whether taken upon himself or thrust upon him — to be the ‘American imam,’ to be the ‘New York imam,’ to be the ‘accommodationist imam.’ ”

Akbar Ahmed, chairman of Islamic studies at American University, said Mr. Abdul Rauf’s holistic Sufi practices could make more orthodox Muslims uncomfortable, and his focus on like-minded interfaith leaders made him underestimate the uproar over his plans.

“He hurtles in, to the dead-center eye of the storm simmering around Muslims in America, expecting it to be like at his mosque — we all love each other, we all think happy thoughts,” Mr. Ahmed said.

“Now he has set up, unwittingly, a symbol of this growing tension between America and Muslims: this mosque that Muslims see as a symbol of Islam under attack and the opponents as an insult to America,” he added. “So this mild-mannered guy is in the eye of a storm for which he’s not suited at all. He’s not a political leader of Muslims, yet he now somehow represents the Muslim community.”

Andrew Sinanoglou, who was married by Mr. Abdul Rauf last fall, said he was surprised that the imam had become a contentious figure. His greatest knack, Mr. Sinanoglou said, was making disparate groups comfortable. At the wedding, he brought together Mr. Sinanoglou’s family, descended from Greek Christians thrown out of Asia Minor by Muslims, and his wife’s conservative Muslim father.

“He’s an excellent schmoozer,” Mr. Sinanoglou said of the imam.

Mr. Abdul Rauf was born in Kuwait. His father, Muhammad Abdul Rauf, graduated from Cairo’s Al-Azhar University, the foremost center of mainstream Sunni Muslim learning. He was one of many scholars Egypt sent abroad to staff universities and mosques, a government-approved effort unlikely to have tolerated a militant. He moved his family to England, studying at Cambridge and the University of London; then to Malaysia, where he eventually became the first rector of the International Islamic University of Malaysia.

As a boy, Feisal absorbed his father’s talks with religious scholars from around the world, learning to respect theological debate, said his wife, Daisy Khan. He is also steeped in Malaysian culture, whose ethnic diversity has influenced an Islam different than that of his parents’ homeland.

In 1965, he came to New York. His father ran the Islamic Center of New York; the family lived over its small mosque in a brownstone on West 72nd Street, which served mainly Arabs and African-American converts. Like his son, the older imam announced plans for a community center for a growing Muslim population — the mosque eventually built on East 96th Street. It was financed by Muslim countries and controlled by Muslim diplomats at the United Nations — at the time a fairly noncontroversial proposition. Like his son, he joined interfaith groups, invited by Mr. James of St. John the Divine.

Hostage Crisis

Unlike his son, he was conservative in gender relations; he asked his wife, Buthayna, to not drive. But in 1977, he was heading the Islamic Center in Washington when he and Buthayna were taken hostage by a Muslim faction; it was his wife who challenged the gunmen on their lack of knowledge of Islam.

“My husband didn’t open his mouth, but I really gave it to them,” she told The New York Times then.

Meanwhile, the younger Mr. Abdul Rauf studied physics at Columbia. At first, he recalled in interviews last year, it was hard to adjust to American social mores. By 1967, he and a Yale student, Kurt Tolksdorf, had bonded at summer school over their shared taste in women and fast cars. But Mr. Tolksdorf said his friend never subscribed to the “free love” of the era.

When the 1967 war broke out in the Middle East, Mr. Tolksdorf said, Mr. Abdul Rauf reacted calmly when Israeli students tried to pick a fight. A classmate, Alan M. Silberstein, remembers debating each day’s news over lunch.

“He was genuinely trying to understand the interests of American Jews — what Israel’s importance was to me,” he said. “There was a genuine openness.”

In his 20s, Mr. Abdul Rauf dabbled in teaching and real estate, married an American-born woman and had three children. Studying Islam and searching for his place in it, he was asked to lead a Sufi mosque, Masjid al-Farah. It was one of few with a female prayer leader, where women and men sat together at some rituals and some women do not cover their hair. And it was 12 blocks from the World Trade Center.

Divorced, he met his second wife, Ms. Khan, when she came to the mosque looking for a gentler Islam than the politicized version she rejected after Iran’s revolution. Theirs is an equal partnership, whether Mr. Abdul Rauf is shopping and cooking a hearty soup, she said, or running organizations that promote an American-influenced Islam.

A similar idea comes up in the video of his visit to Cairo this year. Mr. Abdul Rauf, with Ms. Khan, unveiled as usual, beside him, tells a questioner not to worry so much about one issue of the moment — Switzerland’s ban on minarets — saying Islam has always adapted to and been influenced by places it spreads to. “Why not have a mosque that looks Swiss?” he joked. “Make a mosque that looks like Swiss cheese. Make a mosque that looks like a Rolex.”

In the 1990s, the couple became fixtures of the interfaith scene, even taking a cruise to Spain and Morocco with prominent rabbis and pastors.

Mr. Abdul Rauf also founded the Shariah Index Project — an effort to formally rate which governments best follow Islamic law. Critics see in it support for Taliban-style Shariah or imposing Islamic law in America.

Shariah, though, like Halakha, or Jewish law, has a spectrum of interpretations. The ratings, Ms. Kahn said, measure how well states uphold Shariah’s core principles like rights to life, dignity and education, not Taliban strong points. The imam has written that some Western states unwittingly apply Shariah better than self-styled Islamic states that kill wantonly, stone women and deny education — to him, violations of Shariah.

After 9/11, Mr. Abdul Rauf was all over the airwaves denouncing terrorism, urging Muslims to confront its presence among them, and saying that killing civilians violated Islam. He wrote a book, “What’s Right With Islam Is What’s Right With America,” asserting the congruence of American democracy and Islam.

That ample public record — interviews, writings, sermons — is now being examined by opponents of the downtown center.

Those opponents repeat often that Mr. Abdul Rauf, in one radio interview, refused to describe the Palestinian group that pioneered suicide bombings against Israel, Hamas, as a terrorist organization. In the lengthy interview, Mr. Abdul Rauf clumsily tries to say that people around the globe define terrorism differently and labeling any group would sap his ability to build bridges. He also says: “Targeting civilians is wrong. It is a sin in our religion,” and, “I am a supporter of the state of Israel.”

“If I were an imam today I would be saying, ‘What am I supposed to do?’ ” said John Esposito, a professor of Islamic studies at Georgetown University. “ ‘Can an imam be critical of any aspect of U.S. foreign policy? Can I weigh in on things that others could weigh in on?’ Or is someone going to say, ‘He’s got to be a radical!’ ”