Everyone wants to be called a “Comeback Kid.” John McCain, Hillary Clinton, and now, secular Judaism! The favorably reviewed PBS three-part documentary, The Jewish Americans, is characterized by the dean of American Jewish historians, Jonathan Sarna, as more evidence that, “now, like the proverbial phoenix, Jewish secularism is making a comeback.” What is Jewish secularism? Does The Jewish Americans take us back to a bygone era of Jewish secularism? Will Jewish secularism be the savior of 21st century American Judaism?

Let’s first understand the term. Jewish secularism, as it is commonly understood, is the embrace of Jewish culture as a unifying force for the Jewish people, without the structure and strictures of Jewish religious life. It is Judaism sans synagogue. Jewish secularism flourished in the early 20th century, the heyday of Yiddish, socialism and American Jewish propinquity, that is, dense and intense Jewish urban neighborhoods like the legendary Lower East Side in New York and old West Side of Chicago. Jewish secularism waned when Jews moved to diffuse suburban communities and the synagogue became for many the new anchor of their ethnic Jewish identity.

Most suburban Jews in the late 1940s, ‘50s and ‘60s emulated their Christian neighbors’ church-consciousness and embraced synagogue membership and community, particularly during their child-rearing years. Increasingly, though, that generation’s children and grandchildren were neither religious nor secular. They became recreational Jews who embraced intermittent Jewish expression but eschewed a Jewish lifestyle. Nonetheless, the synagogue was and, notwithstanding all its current challenges, continues to be the primary creator and glue of Jewish community in America.

Fast forward to the 21st century. Today, outside of a growing and increasingly youthful Orthodoxy, Jewish 20- and 30-somethings, descendants of late 19th and early 20th century immigrants, are marrying less, later and/or out of the faith, are distant from synagogue life, and clustered (once again) in urban centers. Some long for their Jewish roots and are embracing a revived secular Judaism reminiscent of the Jewishness portrayed in The Jewish Americans, but with a very modern flavor. They move to the beat of Matisyahu, blog on Jewcy.com and empathize with Shalom Auslander, Orthodoxy’s Philip Roth. They are leading a Jewish cultural renaissance in America. Yet many fully embrace American openness and are uncomfortable with Jewish peoplehood, and its preference for in-marriage.

Are they the harbingers of a nascent movement towards a new secular Judaism? Maybe, but if so, the movement appears more different from than similar to its predecessor of a century ago. Above all, today’s young Jewish adults have not yet succeeded in creating Jewish community within a secular context the way their forbearers did. By contrast, the secular Jewish community of the early 20th century was able to go beyond the celebrated arts and wisdom of the Yiddish theater and the Forward to produce a fraternal and social structure that bound Jews together with a sense of shared values, traditions and destiny. These included a common language, Yiddish. But this secular Jewish structure did not last beyond a couple of generations. It did not have the power of generational continuity in an open America that both seduced and invited Jews to assimilate, particularly following World War II.

We are living in a challenging and transitional moment in American Jewish religious life. The synagogue as an institution continues to be under attack as uninspired, slow to change and unable to retain its membership rolls. But the synagogue will and can change – many congregations have already – and must endeavor to incorporate within its ethos the Jewish cultural emergence that a new generation of American Jews has produced. Why the synagogue? Because it continues as the Jewish institution that, more than any other in Jewish communal life, has the ability to attract the greatest number of Jews at some point in their adult lives. The synagogue is still perceived as the standard-bearer of Jewish authenticity, where the ancient mystery of congregational prayer and song, the compelling nature of Jewish life-cycle events and the pull of community can all crystallize. Those federations that are serious about rejuvenating Jewish life in their communities have now invested in synagogues, affirming their status as primary gateway institutions. Without religious community, there is no Jewish continuity.

Perhaps the new secular Judaism will engage our disengaged 20- and 30-somethings. That’s the good news. But how can we ensure that its expressions will become treasures to be passed down to children and grandchildren, rather than phenomena of the here-and-now? The answer is to imbue these cultural expressions of Jewish identity with substance and make them transmittable. The first task requires strong and persistent Jewish education. The second goal, to facilitate the bequest from one generation to the next, ultimately requires a formal religious structure. And for that, there’s simply no substitute for our synagogues. For the last 2,000 years, no institution has rivaled its power to sustain the Jewish people.

Noam Marans is the associate director of AJC’s Department of Contemporary Jewish Life.