Celebrating Shabbat on Friday nights can be a little like going to the gym, says Matthew Mercurio. “There are a lot of ways to talk yourself out of it,” he notes, “but if you commit, you will feel so good afterward.”

That’s why the San Anselmo resident organized Shabbat Swap, a year-old program that matches host families with people desperately seeking wine, candles and a little Jewish hospitality.

Though Mercurio is a member of Tiburon’s Congregation Kol Shofar, and many of the program’s participants are synagogue members,  Shabbat Swap is open to the entire Jewish community, in the North Bay and beyond.

“Friday night tends to be de-emphasized among Marin Jews,” Mercurio says. “Mostly they want fellowship. It’s much more about meeting people in your community and having lasting friendship.”

Like Mercurio, Brenda Gates-Monasch of Novato has hosted numerous Shabbat Swaps in the last 12 months, welcoming strangers into her home on Friday nights. They don’t remain strangers for long.

“For people who participate, it’s a very positive impact,” says Gates-Monasch. “It allows for and encourages creation of bonds. It makes it easier to break into a community that many perceive as closed.”

Sharren Rosenthal of Tiburon remembers feeling thrilled about Shabbat Swap when she initially looked into it. Her first time, she was a guest at the home of Mercurio and his wife, Robyn. She loved the experience and went back several times.

“Normally we do Shabbat at home,” she says, “but it’s always nice to meet new Jewish people who care about the same things you do. This creates a sense of community. And unaffiliated are just as welcome as affiliated.”

As for her host, Rosenthal adds, “When people move into the community I give them Matt’s e-mail and say, ‘This guy can hook you up.’ ”

Mercurio jokes that Shabbat fellowship became important to him because, as a convert to Judaism, he never had the chance as a youth to go to Jewish summer camps and learn the proper Shabbat songs.

A native of Houston and raised Methodist, Mercurio became interested in Judaism while living in Washington, D.C. He attended a synagogue there that had its own version of Shabbat Swap.

“You would e-mail in saying whether you were looking for a Shabbat dinner or if you had space,” he explained. “[The swap] took place on the bimah after Friday night services. Someone would say, ‘OK, who’s looking?’ ”

An economist with a private firm, Mercurio relocated to Marin County in 2005. He eventually joined Kol Shofar, where he completed his conversion. All along, he and his wife hosted kosher Shabbat dinners, and soon enough he started wondering if a Shabbat Swap program would take off in Marin.

It did.

The Mercurios have hosted more than a dozen times, and always take “the overflow,” when some people seek a place at the Shabbat table at the last minute. Mercurio admits there is a selfish aspect to all this mitzvah making: He loves meeting new people.

“People send me e-mails saying it was great,” Mercurio adds. “They see me at shul on Saturday and thank us for doing this.”

For participants like Gates-Monasch, the swap means more Jews get to participate in the most important ritual of the week.

“It means Friday night becomes the beginning of Shabbat,” she says. “Not necessarily to have a gourmet meal designed to impress the food critics, but to think about the blessings we have. I’m always reminded: More than the Jews have kept Shabbat, Shabbat has kept the Jews.”

For more information about the Shabbat Swap program e-mail [email protected], or call (415) 453-2737.