Fourth-graders at Milton Academy have just completed a year studying the Middle East, and they are celebrating with a party. Tables at the private school are spread with plates of hummus, falafel, and dried fruit. Children are posing for photos in head scarves and robes. A bazaar has been set up in a classroom, where guests are encouraged to haggle over the price of postcards and tiny souvenir cedar trees.

About a dozen students from the Islamic Academy of New England have joined the Milton class as part of an exchange. After lunch, a teacher from the small Muslim school in Sharon, known to his students as Mr. Mahboob, leads the noon prayer in the gym.

Wearing a long black tunic, a skullcap, and leather socks, the teacher goes through the ritual of bowing, standing, kneeling, and lowering his forehead to the floor while praising Allah in Arabic. Behind him, students from both schools arrange themselves in segregated rows, boys in front of girls, and try to follow along.

Mahboob, born John Henshaw, doesn't fit the typical profile of an ambassador for the Muslim world. Blond and more than 6 feet tall, he is a former prep-school football player who grew up in nearby Dedham, the son of a private-school teacher and a lawyer. His ancestors sailed on the Mayflower and fought in the Civil War. He was christened in the Episcopal Church with a string of family names, John Marshall McCormack Henshaw, or Marshall for short.

Yet he is a Muslim, what he calls "a traditional, conservative Muslim." Ten years ago, as a teenager at St. Mark's School in Southborough, he accepted Islam as his true faith and added to his lengthy name a new tag, Mahboob. That adolescent decision has shaped every aspect of his life since then and landed him on the far side of a cultural divide.

"That was funny," says Henshaw as the service breaks up. "I've never led a bunch of non-Muslims and Muslims in prayer in a gymnasium before."

Even before the September 11, 2001, terrorist attacks, a preppy American teenager's converting to Islam was an unusual step. Choosing to become a conservative Muslim means embracing a lifestyle completely outside the American mainstream. At age 25, Henshaw doesn't drink alcohol, date, or listen to popular music. He has spent months in Pakistan, India, Saudi Arabia, Egypt, and Syria, worshiping with other Muslims and visiting mosques. When he's in the United States, whether at the nondescript triple-decker that serves as a mosque in Roxbury or the Islamic school in Sharon, Henshaw is used to being in the minority, one of the few white, American-born men in a room full of Middle Eastern and south Asian immigrants, children of immigrants, and African-Americans.

I'VE KNOWN HENSHAW HIS ENTIRE LIFE. HIS FAMILY HAS LIVED across the street from my parents' home in Dedham for 25 years, and his older sister is my lifelong friend. I remember when Henshaw became a Muslim at around 15. I sat next to him at his mother's Christmas Eve party, where he declined to eat a dessert made with vanilla because it contained forbidden alcohol. The general impression then was that he was going through a phase.

Indeed, he strayed from strict observance for a couple of years at college, where he partied, had a girlfriend, and hung out with what he calls "preppy, private-school, frat-boy types." But over time, he has made Islam a focus in his life. At Harvard, he majored in Near Eastern languages and civilizations, and at the baccalaureate ceremony during graduation, he read a passage from the Koran in Arabic. He's had jobs teaching at the Islamic school and working for a finance firm that specializes in investments that comply with Islamic law.

For Henshaw, negotiating life as a contemporary-preppy-American-conservative-Muslim involves constantly shifting between cultures. It means praying five times a day, yet not objecting when his sister plays Eminem in the car. It means spending a weekend in Maine worshiping with Somali immigrants at the Lewiston mosque before visiting his father at the family's Brunswick farm.

"It is a struggle," he says. "I feel more like I am something of an outsider on both sides, because I'm straddling two worlds, but I don't feel

Until recent government restrictions on immigration, Islam was the fastest-growing faith in the United States, thanks to a combination of Until recent government restrictions on immigration, Islam was the fastest-growing faith in the United States, thanks to a combination of like people are rejecting me."

Until recent government restrictions on immigration, Islam was the fastest-growing faith in the United States, thanks to a combination of immigration, population growth, and conversion, says Yvonne Haddad, a professor at Georgetown University who has studied Muslims in the United States. There are no US government numbers on Muslims in the United States; estimates range from 2 million to 8 million, depending on who is counting. But without question, the growth in the Muslim community has been dramatic, Haddad says, considering that a 1960 survey reported 78,000 Muslims in the United States. A 2000 study released by the Council on American-Islamic Relations reported that half of the 1,200 mosques in the country researchers counted that year had been founded since 1980. According to that report, some 20,000 Americans converted to Islam in 2000.

Henshaw describes his own discovery of Islam as "miraculous." St. Mark's School is an unlikely place for a young person to find Allah. The 138-year-old Southborough prep school is nominally Episcopalian, and the teenagers who go there tend to be more concerned with getting into a good college than finding their way to Eternal Paradise.

Henshaw arrived at St. Mark's in 1992, following a long family tradition. At 14, he was a good student but shy. In his first weeks, he struggled to adjust.

One Saturday night, he was moping around the dorm when he followed the aroma of spicy food to a room where a classmate was eating chicken curry with his brother. The classmate, a Kenyan-born student of Indian descent who was an enthusiastic Muslim, shared his meal with Henshaw. That night, Henshaw made a new friend and picked up a jocular nickname, Mahboob Chaiwala, or "beloved tea seller," later shortened to Mahboob.

As Henshaw got to know his Muslim friend, the boys would talk about Islam. The basic tenets of the faith, with its emphasis on one God, made immediate sense to Henshaw. "I think I always had an innate belief in God," he says. He also describes himself at that age as "very moralistic" -- shocked by classmates who were smoking cigarettes or drinking -- and so the strictures of the faith were appealing.

His conversion was gradual. He gave up pork early on, as a test of willpower. When Houston Rockets player Hakeem Olajuwon spoke at a St. Mark's assembly about his life as a Muslim, Henshaw was inspired to pray for one of the first times in his life, in a dorm room alongside the basketball star.

At the same time, two other classmates from the Boston area who were close to Henshaw's Muslim friend were also developing an interest in Islam. One spring weekend, the four boys took a road trip to New York to visit a mosque. On the highway, they stopped at a McDonald's, where they performed the ritual cleansing of their hands and feet in the restroom and then prayed together on rugs they laid out in the parking lot. Henshaw had never prayed in public before. The entire experience deeply affected him.

From the beginning, Henshaw was attracted to the rigor of Islam and the conviction of the Muslims he knew. The message was similar to what he'd heard in church, he says, but it seemed more urgent.

"The purpose of life was put into much starker definition. There is a hereafter, and this is how it happens, and then they explain exactly what happens on the Day of Judgment in great, great detail," he says. "It made a lot of sense to me, and the people's real belief had a strong effect on me."

As it happened, Henshaw was the last of the St. Mark's group to convert. Before the end of that school year, his freshman term, the two other classmates had accepted Islam. Henshaw made his decision that summer.

Over the years, the four young men would become best friends. During college, when three were in Boston and one in Colorado, they kept in touch. When Henshaw was at Harvard and had, for the most part, stopped practicing, he continued to go to mosque on Fridays, because one of his St. Mark's friends, Noor ad-Deen, would show up at his dorm to go with him.

"I think having these friends has been extremely important. It's a collective thing," says Noor ad-Deen, who asked to be identified by his Muslim name.

Noor ad-Deen, who grew up in South Dartmouth in a "nominally Christian" family, now lives in Cairo, where he studies Arabic and is married to an Egyptian woman. The other St. Mark's convert, who lives on the North Shore, is married to a Bengali woman. The couple is so strict about segregation of the sexes that Henshaw doesn't know the woman's name. None of the friends, Henshaw says, expected their lives to be so shaped by their acceptance of Islam.

When you see Henshaw today, there's no mistaking that he's a Muslim. He sports a full, reddish beard. He usually dresses in a long shirt-dress (called a dishdasha) worn over his pants, a skullcap, and leather socks that allow him to pray throughout the day without having to repeat the ritual washing of feet. I have seen him wearing these clothes in Dedham while shoveling his parents' driveway, with a parka zipped over his robe, or trudging up the street from the train station to his house.

Henshaw wears these garments to imitate Islam's seventh-century founder, Mohammed, and to make a statement about his identity. In his robe and beard, he can go to any city in the world and immediately be welcomed by other Muslims as a "brother." It's the same reason why he generally uses his Muslim name.

"Listen, if I don't do these things, as a white American, it's very easy to turn on and off my Islam," he says. "It'd be very easy to lead a double life."

Henshaw describes himself as "orthodox." He prays five times a day, avoids prohibited food, and doesn't socialize with women. At the mosque he usually attends, only men meet to pray; their wives and daughters gather separately, in private homes.

Henshaw's outlook on Islam has been greatly influenced by a conservative Islamic movement called the Tablighi Jamaat, a group founded in India in 1927 that is considered to be the most widespread revivalist Muslim movement in the world. Beginning when he was in college, Henshaw has gone on Tablighi Jamaat proselytizing pilgrimages in New England, the Midwest, Great Britain, India, and Pakistan, and last summer he traveled from Pennsylvania to North Carolina promoting the practice of strict Islam among other Muslims.

The Tablighi Jamaat is expressly apolitical and, in the United States, intentionally keeps a low profile, although in the past two years it has received some negative attention linking it to extremists. Notably, American John Walker Lindh was reported to have traveled with the Tablighi Jamaat before linking up with the Taliban fighters in Afghanistan. The New York Times reported in July that law enforcement officials believe some terrorists have used the group as a cover. Law enforcement officials were quoted as saying that terrorists used the group as a recruiting ground for terrorists looking for Muslims drawn to extremist teachings, a charge that the group's leaders reject.

"I've definitely never seen anything like that myself," Henshaw says.

In general, Henshaw bristles at the suggestion that practicing a conservative brand of Islam is connected to being an extremist. He sees fundamentalism as "practicing the fundamentals of the religion" -- not something dangerous.

"It's hugely problematic to say Islam encourages people to adopt extremism. We don't suggest that Christianity does that just because there are some guys going around killing abortion doctors," he says. "You can try to implement Islam in a traditional manner while still acting in a positive way in the world."

With his robes and beard and well-worn passport, Henshaw is aware that some people may view him with suspicion. "The profile is similar to a John Walker Lindh," he says. He tells me he's surprised that he has never been detained while traveling. But Henshaw insists the Islam he practices is spiritual, not political, and he doesn't see himself as rejecting American values: "I certainly don't see leading a fairly conservative Muslim lifestyle as in any way encroaching on the rights of others, if it's a spiritual thing."

Practicing Islam successfully, however, does mean creating an Islamic environment. Henshaw thinks it's important for Muslim children to go to Islamic schools. When he sets up his own household, he expects that visitors to his home will socialize in sex-segregated groups. He hopes to have a wife whose primary focus, even if she has a job, will be raising children to be good Muslims.

"Sometimes my dad's like, 'Well, we let you become a Muslim, what if your kid wants to become Hindu?' " Henshaw says. "And I say, that's not going to fly."

When Henshaw and I were talking last spring, he was living with his mother and stepfather in their 320-year-old house in Dedham. He had finished the job working for a finance firm in South Africa and had come home to look for work.

Though he doesn't mingle with women on his own time, he is comfortable meeting and talking with his parents' friends in their home. The only surprising thing I notice him do is shoo away the family's beloved dog, Rocky, because, he tells me, he believes touching dogs is impure.

Henshaw grew up in the Dedham house with his parents, two half-brothers from his father's previous marriage, and a half-sister from his mother's previous marriage. When he was in the second grade, his parents divorced, and his father moved to Hingham. By the time Henshaw was in high school, his parents had remarried, and he remains close to both.

Neither of his parents was especially religious, and neither was fazed by Henshaw's initial interest in Islam. "In some ways, having these liberal, noncommittal Northeast intellectual parents has made my life easier," he says. His mother and father liked his St. Mark's Muslim friends, and they saw the advantages of having their teenager adopt a doctrine that prohibits drinking alcohol or taking drugs. It didn't seem out of character that he would gravitate toward a religion with strict rules, but they also assumed he would grow out of it. Henshaw jokes, "I think my dad probably saw it as a ticket to getting into a good college: My son's too white. Oh, good, now he's Muslim."

Over time, however, Henshaw's parents have accepted that their son's religion is a central part of his life and have continued to support him. His mother, Tyler Knowles, recently took a course on Islam, and she and her husband, Larry Flood, a few years ago traveled to Syria with Henshaw on a family vacation. "We have friends who sort of roll their eyes," Knowles says.

The September 11 terrorist attacks created complicated fears for Henshaw's parents. At the time, Henshaw was at a mosque in India, having just spent a few weeks in Pakistan with the Tablighi Jamaat. Knowles and Henshaw's father, Weld Henshaw, were worried for their son's safety and anxious about anti-Muslim feeling at home. Then came the news of the arrest of Lindh. Like Henshaw, Lindh was the son of affluent, liberal, divorced parents, and spent weeks at a time traveling abroad with Muslim groups.

"I really did have the feeling, there but for God goes my son," says Knowles. She wanted to write to Lindh's parents but was afraid any sign of support would make Henshaw a subject of suspicion. Henshaw's siblings relate to him -- and his religion -- in their own ways. Steve Henshaw, 39, who works for a medical response company in Framingham, has for years practiced a variety of Eastern and Western religions and now goes to mosque as well.

Henshaw's sister, Stephanie Knowles, 32, a New York artist, wrangles with her brother over women's issues. "That's the one thing about his being Muslim that really irritates me. How did he grow up in a house with a single mom for a portion of his childhood and now he's in this thing where the woman he looks to be with is going to have all these restrictions?" she says. "I feel like we were so different from that, and it's sort of insulting in a way."

Henshaw doesn't rationalize the rules he follows. "If you accept the fundamental tenet, that this religion is coming from God, it is your responsibility to implement the whole message to the best of your ability," he says. "At the end of the day, we're not the judge. God is the judge, and he knows best."

One of the challenges of being a 25-year-old devout Muslim guy in Boston is finding what Henshaw calls "halal fun." He learned this when he returned to Harvard after a semester in Egypt, where he recommitted himself to Islam. Upon his return, he gave up his bedroom in a 16-person dorm-room suite in order to live in a party-free off-campus apartment with Muslim roommates.

Now, the friends he sees are virtually all Muslims. In his free time, he plays a fair amount of basketball, and he often spends his weekends at social gatherings organized by his mosque. While I was with him, his mobile phone rang regularly with calls from male Muslim friends.

Still, Henshaw doesn't think it's normal for people to spend their 20s apart from the opposite sex. He would like to get married soon. "I think if I were not Muslim, marriage wouldn't be something I'm thinking about at this point," he says. "But the whole idea of not interacting with women before marriage only works in a society where you marry early."

Given his restrictions, in order to find a wife, Henshaw must meet one through friends. He thinks making a match would be easier if he came from a Muslim family and his female relatives were involved. Ideally, he'd like to find a wife who will be comfortable mixing in non-Muslim environments, such as Thanksgiving dinner with his mother's extended family in Virginia. The most important quality he is looking for in a wife is her commitment to Islam, which he hopes to be the basis of his family life.

"I think when there's some spiritual basis of the relationship, a sense of trying to live together and grow together as good Muslims," Henshaw says, "I think it will probably strengthen the relationship and put it on a different plane."

I go to meet Henshaw at the school in Sharon where he is teaching social studies. The Islamic Academy of New England is tucked away on a former horse farm, surrounded by woods. I pull in next to a car with a bumper sticker that reads: "The most excellent jihad is one against the self."

The school is cheerful. The walls are decorated with children's artwork, including colorful drawings of Arabic letters. A group of boys dressed in white shirts and long dark pants is playing basketball on an outdoor court. In the backyard, girls wearing head scarves and long skirts play softball. As we tour the mosque, Henshaw talks about one of his far-off dreams, which is to start a Muslim prep school modeled on St. Mark's but offering an Islamic environment.

At 25, Henshaw is still deciding what kind of career to pursue. He found that he wasn't fulfilled working at an Islamic finance firm. He's drawn to college-level teaching about Islam, but he doesn't know if there's room for devout Muslims in American universities. He's not sure if he would fit into a big law firm or bank.

"There are very committed Muslims, even Muslims with big beards who dress in these clothes who work in corporate America. People get used to it," he says. "But I found when I've tried to do it that it has been difficult."

The question of what to do for work worries him only so much. As long as he's practicing his faith, he has peace of mind. "The big-picture questions are solved for me, in terms of what life is all about, what happens after you die, what are the things you should really make the most effort for," he says.

In the meantime, he enjoys teaching. At the school, Henshaw often sees immigrant parents who are anxious about raising Muslim children in America. Although, as an American, he knows the issue is different for him, he often thinks about aspects of his life -- from finding a wife to fasting during Ramadan -- that would be easier for him if he lived in a Muslim country.

A few weeks later, he solves his dilemma for a year when he accepts a job teaching at a private school in the United Arab Emirates. It is not an Islamic school, but the dominant culture in the city of Sharjah is Muslim.

Henshaw can see himself staying in the Middle East if he finds that he loves his job or if, as he puts it, "something happens on the marriage front." For now, though, he is thinking of the posting as a yearlong commitment, after which he will probably return to the United States.

Earlier in the summer, he explained to me the conflicting emotions he feels about settling abroad. It was a hot day, and he had taken off his robe, and was sitting in his olive-green golf shirt talking about heading up to Blue Hill, Maine, where his mother and stepfather spend the summer.

"When I'm here, I'm always thinking it's so nice to have a mosque around every corner. It's so nice to hear the call to prayer," he says. "But when I'm in the Middle East, I'm thinking about the climate in New England. I'm thinking about Blue Hill. I'm thinking about playing golf and tennis, and I want to go home."

© Copyright 2003 Globe Newspaper Company.