Still, it seems that few young people have an interest in joining. Of the dozen I interviewed at Adas, no one plans soon to put down permanent roots (financial or spiritual) in a synagogue. Stacy Miller, a 29-year-old teacher, tells me that she has set up a social group for Jewish young professionals in Northern Virginia. She will join a synagogue “some day,” but “right now, I get to go to different places and meet new people.”

With a half an inch of snow on the ground, it felt like this city was shutting down on a recent Friday evening. Yet more than 300 people—mostly young adults—streamed into Adas Israel, a conservative synagogue in the Cleveland Park neighborhood. Many were there to “Shabbat-hop.”

The idea (cooked up in 2007 and now sponsored by the local Jewish Federation and an organization called NEXT DC) is to get young adults to try a new synagogue each month. The concept of “hopping” doesn’t generally bring smiles to religious leaders. Those leaders have heard that members of Generation Y fear commitment, don’t like institutions, and prefer to act like a roving urban tribe texting their whereabouts.

But inside Adas Israel there is warmth. The hundreds of chairs are arranged in a circle around a cantor and two musicians as they offer a lively and moving service. For an hour and a half, people sway, clap and sing. The Shabbat-hoppers are clustered on one side of the room. They embrace friends who come in late and do some chatting, but it doesn’t distract from the calming service at the end of a long week. They stay for a buffet dinner and linger until nearly 10 p.m.

Jenna Lowy, a 27-year-old fundraiser who has lived in Washington for five years, says that her “hesitation in going to services before has been not knowing anyone.” But coming with a group has made it easier. Becky Porter, the co-chair of Shabbat Hopping this year, tells me that her boyfriend lived next door to a synagogue in Bethesda, Md., but whenever he would go “no one would approach him to welcome him.” So he started to Shabbat-hop.

Erica Brown, a prominent rabbi in Washington, recently wrote an article complaining about a “customer service” problem in the Jewish community. “We walk into synagogues and schools . . . and no one says hello. Few know our names (maybe for months or years). A friend in an interfaith marriage says that when he takes his wife to shul, no one talks to them. When he goes to his wife’s church, everyone comes over to greet them.”

[Editor’s note: This article is incomplete. The source for this document was originally published on online.wsj.com—however, the original URL is no longer available.]