Stuart Blumberg remembers the days when he was a struggling writer, rooming in New York with his buddy, Edward Norton, the struggling actor. Every evening, Blumberg arrived home late, whereupon he and Norton settled in front of the TV with a couple of pizza slices. They popped "Raging Bull" or the British cult film, "Withnail and I," into the VCR. "We watched those same two movies again and again," Blumberg recalls. "It was like meditation while we were eating. And we said, 'Wouldn't it be great one day if we could make a movie together?'"

The old friends have at last fulfilled their dream. Norton, now one of the most acclaimed actors of his generation, is directing and starring in Blumberg's comic screenplay, "Keeping the Faith," about two old friends, a priest and a rabbi, who fall for the same Irish Catholic woman (Jenna Elfman), a long-lost childhood pal. Hip Rabbi Jake Schram (Ben Stiller), who brings gospel choirs and meditation to his Upper West Side shul, is a "proxy" for Blumberg, who like the protagonist is charismatic and has had moments of commitmentphobia.

The fictional priest Brian Finn, meanwhile, is not unlike Norton. "There is a sweetness to the character that reminds me of Ed," Blumberg says. And a certain meticulousness, too.

Norton played Felix to Blumberg's Oscar when the two shared modest apartments in New York's East Village and Upper West Side. "I'm much cleaner now," insists Blumberg, who turned 30 on the set, along with Norton. "But in those days, I'd have a lot of quarters lying around for the laundry; he'd clean up after me, and he'd get so angry that he'd take my quarters as, like, a form of recompense."

Edward Norton and screenwriter Stuart Blumberg.

Nevertheless, the two young men worked as writing partners for a time, collaborating on, among other endeavors, an evening of sketch comedy off-off-Broadway. "We also wrote a comedy script that, to this day, we will never show anybody," Blumberg confides.

Norton grew up in a privileged, nonreligious Gentile home in Columbia, Md., where, he says, he was an "honorary Jew."

"If you go to more than 10 Bar Mitzvahs you get an 'honorary Jew' certificate, and I went to at least 10 the year I was 13," he explains. "I was drunk on Manischewitz for half of 1983."

Blumberg, meanwhile, grew up in a Conservative Jewish home in Cleveland, the grandson of avid Zionists who emigrated to Israel in their 70s. One set of his great-grandparents helped found the Society for the Advancement of Judaism, a Reconstructionist synagogue in New York. Blumberg, for his part, attended the Agnon Jewish day school in suburban Cleveland through fifth grade. Like the fictional Jake, he pondered whether to date non-Jews.

On the one hand, his parents made it clear they would prefer that he date Jewish girls; on the other, his first serious girlfriend was a biracial Presbyterian his mother doted upon. "So there was a dialectic, a tension surrounding the issue," says Blumberg, who now has a Jewish girlfriend. "It was not black-and-white. It was in the gray area."

As it happened, a classmate who was half-Jewish and half-Japanese helped introduce Blumberg to Norton at Yale. She was "straight-ahead, funny, sharp," an inspiration for Elfman's character in "Keeping the Faith," Blumberg says, though there never was a romantic triangle among the three.

Blumberg and Norton became fast friends in the theater department, where they shared a funny scene together in "A Midsummer Night's Dream." But it wasn't apparent that Norton was destined to become a star. "His acting style is so subtle that I think it was overlooked," Blumberg says. "He is great onstage, but I think that film, which records such small movements and nuances, is very well suited to Ed. If people didn't see his [ability] before, it was because they weren't looking closely enough."

Norton, the unknown, became the Hollywood It Boy after he won an audition over 2,100 other actors and secured the role of the sociopathic altar boy in "Primal Fear." Thereafter, he portrayed an idealistic attorney in "The People vs. Larry Flynt," a neo-Nazi thug in "American History X" and a nihilistic cult leader in "Fight Club," among other roles. Along the way, he earned two Academy Award nominations.

Blumberg, meanwhile, toiled as an investment banker and as a writer for the comedy series "Mad TV" while deferring admittance to Columbia law school. In the end, it was Norton who dissuaded him from pursuing the "sensible" career. "He said, 'Don't just do it for the stability; follow your heart,'" Blumberg recalls.

Not long thereafter, the writer showed Norton an early draft of "Keeping the Faith," born of his own deepening fascination with religion, which now includes attending Temple Shalom for the Arts and Metivta: A Center for Contemplative Judaism in Los Angeles. Norton decided to co-produce, and, with some encouragement from Blumberg, to make the movie his directorial debut.

The draw, apparently, was the chance to work on a film that was far lighter in tone than his recent endeavors; call it the anti-"Fight Club." "To me, the most punk rock thing you could possibly do now, in 2000, is to make a comedy that is... cool, but that's completely square in its total straightforwardness," he told W magazine. "The most clichéd thing you could do now is ironic detachment, that cynical cool, which has become an utterly boring cliché."

As research, Norton and Blumberg attended a Catholic mass in Santa Monica, where they scribbled notes on the hymnals. They attended a Shabbat service at B'nai Jeshurun, the hip Upper West Side synagogue where music is a staple of Friday night worship. (Norton, incidentally, has a friend whose great-uncle was Rabbi Marshall Meyer of B'nai Jeshurun, who transformed the once-dying shul into a thriving yuppie congregation.) Meyer, in a way, is a model for the fictional Jake.

To prepare for his role, Stiller -- the son of a Jewish father and an Irish motherwho converted to Judaism -- tagged along with bachelor Rabbi Hillel Norry on the Upper West Side. He asked blunt questions such as "Can you date non-Jewish women? Can you date someone in your congregation? Do you have to keep kosher?'"

In the film, his character collects "Heroes of the Torah" cards, which are like baseball cards except that they depict bearded, payess-wearing rabbis. "Jews don't flagellate themselves," he tells an angry Finn at one point. "They plant trees."

Of course, some Jewish viewers may be offended by the movie, which could be perceived to portray negative Jewish stereotypes. But Norton staunchly denies that there will be any kind of backlash to the film.

"The Jewish jokes get the biggest laughs from Jewish viewers, and the Catholic jokes get the biggest laughs from Catholic viewers," he says. "That's because the context of the story is a positive discussion of the tensions and challenges of keeping one's faith in contemporary culture."

"Keeping the Faith" opens April 14 in Los Angeles.