Midway through Sabbath services on a cold Friday evening in January, Aaron Greenberg, a lay religious leader, stood in front of the congregation at the Vilna Shul, an 86-year-old synagogue in the heart of Boston's Beacon Hill, and told the story of Noah. "After 10 generations," Greenberg said, "God looked down and didn't like what he had made. So he decided to make something better."

The Flood notwithstanding, the tale was well suited to the circumstances. The congregants Greenberg was addressing had gathered on a frigid New England night because four young Jewish businessmen decided that they, too, wanted to make something better. In 2001, Dave Gerzof, Aaron Mandell, Andrew Perlman, and Marc Rubenfeld -- friends and partners in a series of business ventures -- surveyed the spiritual options available in Boston and didn't like what they saw. So they pooled their entrepreneurial experience to develop what they call a learning congregation. The result is Havurah on the Hill, a monthly program lively enough to lure up to 350 people into temple on the most active social night of the week.

The founders say they were motivated by the lack of outlets for spiritual fellowship with people their own age. "There was nothing for us once we graduated from college," says Gerzof, the 29-year-old CEO of a marketing firm called Big Fish Communications. So the four men decided to start a havurah, which in Hebrew means a gathering or community of friends.

Even a spiritual start-up needs an appropriate place of business, and the founders didn't have a location big enough. That is, until Perlman, 29, and Mandell, 30 -- the co-founders of Coatue, a developer and manufacturer of polymer microchips that was recently sold to Advanced Micro Devices -- found a jewel in the rough. While walking to work they stumbled upon the Vilna Shul, an aging brick synagogue built by Lithuanian immigrants just after World War I. Long dormant and rundown, it was one of the oldest synagogues in Boston. After it closed in 1985, it was saved from demolition when a nonprofit acquired it to house the city's first Jewish museum, a plan that's still in development.

After securing permission to use the space for meetings, the Havurah founders began raising money to fund events and to help with the Vilna Shul's ongoing restoration. They also secured two seats on the nonprofit's board of directors. "It was a lot like starting a business," Perlman says.

Once they had a location, the founders instituted an effective division of labor for managing operations. Gerzof would handle marketing; Perlman and Mandell, the most experienced financial hands, would spearhead fundraising; and Rubenfeld, who designs investment software, would manage accounting and Web development, designing an online system to track the congregation's growing pool of members.

But it was the way they designed the gatherings that has made Havurah on the Hill one of the most popular religious events in town. Each month's service features a keynote speaker, who is likely to highlight what Gerzof describes as the organization's entrepreneurial spirit, and culminates in a catered kosher meal. At the January service, the speaker was Jim Gordon, the CEO and founder of Cape Wind Associates, who aims to build a controversial farm of wind turbines on a shoal in Nantucket Sound. Gordon spoke with passion about the importance of renewable energy, and then stepped down from the carved mahogany bimah to join the crowd in a meal of chicken and noodle pudding. "My father used to live in this area of Boston," Gordon said, "and he attended the Vilna Shul before it was closed. We need to get back to those traditions and values." He looked around at the old building, and at the young men and women who filled it to capacity. "There's such a great vibe here."

The vibe Gordon noticed is what compels the gathering's founders to devote time to a venture whose only returns aren't material. "I'm so focused on my business," says Perlman. "But I need to do this. It rounds me out."