The first time I met my future mother-in-law, a professor at Columbia University and a longtime resident of the Upper West Side, she asked me in a challenging tone: “Why do you keep kosher?” I had been dating her daughter for all of two weeks and wasn’t looking to get into a theological or philosophical discussion, so I flippantly replied, “Because I’m a Jet.” I didn’t realize it at the time, but in my invocation of the Stephen Sondheim lyric from West Side Story, I was defining myself as a member of what was to become, over the ensuing quarter century, one of the fastest growing and most dynamic segments of the American Jewish community. Call it “Social Orthodoxy.”

Just like those Jets roaming the streets of Hell’s Kitchen together, I was “never alone” and “never disconnected.” Whether in synagogue or summer camp, making Shabbat dinner with friends or traveling through Israel, I always felt “home with your own” and “well protected.” Being Jewish meant being a member of a club, and not just any club: a club with a 3,000-year-old membership, its own language, calendar, culture, vast literature including histories and a code of law, and, of course, a special place on the map.

Much has been written about the Pew Research Center’s recent survey of American Jews, and most of the coverage has focused on the rapidly increasing pace of assimilation and intermarriage. The survey also revealed another troubling trend: 22 percent of all American Jews describe themselves as having no religion at all, and among Jews under 35, nearly one in three claim to have no religion. Alan Cooperman, deputy director of the Pew survey, painted a dim picture for the future: “It’s very stark. Older Jews are Jews by religion. Younger Jews are Jews of no religion.”

Yet the Pew survey revealed that Orthodox Jews, who make up only 10 percent of the community and are the smallest of the three major denominations, are the youngest segment of the Jewish community, have the most children, and rarely intermarry. This is among the reasons why the historian Jonathan Sarna has called Orthodox Judaism “the great success story of late-20th-century American Judaism,” and all the data suggest the same will be true for the 21st. Among the American Jewish community at large, the birth rate for those ages 40–59 is actually below the national average, with only 1.9 children per adult, and only 1.3 for the non-Orthodox. Within the Orthodox community, the number is 4.1. Twenty-seven percent of Jewish children today are growing up in Orthodox homes.

Just who makes up the Orthodox Jewish community? In popular culture, Orthodox Jews are hard to miss, especially the men: They wear white shirts, long black coats, and black hats, with sidecurls and long beards. This image is not inaccurate: The Pew data revealed that two-thirds of self-identifying Orthodox Jews are “ultra-Orthodox” Haredim (literally “tremblers before God”), and most of them dress much as their ancestors dressed in 18th-century Europe. But there is another segment of the Orthodox community, the Modern Orthodox, who look nothing like their Hasidic-looking co-religionists. This is my community, and it is a success story of its own.

Modern Orthodoxy has its origins in 19th-century Germany, where two leading rabbis, Samson Raphael Hirsch and Azriel Hildesheimer, argued that Jews could no longer seclude themselves behind shtetl walls but instead had to engage with the secular world and embrace modernity. Under the rubric of the catchphrase Torah im Derech Eretz (“Torah with the way of the land”), these rabbis posited that secular education was an affirmative duty for Jews. Hildesheimer even established schools for men and women that taught both religious and secular subjects.

It was in America in the 20th century that Modern Orthodoxy matured intellectually, under the “Rav,” Rabbi Joseph Soloveitchik (1903–93). He made a titanic effort to harmonize rigorous Jewish practice and thought together with all aspects of modernity—and became the champion of what is known as Torah Umadda (“Torah and secular knowledge”). At the same time, Modern Orthodoxy established itself as a social movement within American Jewry. Co-educational high school yeshivas and summer camps were established, as was Yeshiva University, the first institution of higher education in America established to teach both Jewish and secular studies. By the end of the 20th-century, a vibrant community of Modern Orthodox Jews had risen to positions of prominence in medicine, law, journalism, and academia. One was even nominated to be vice president; another became White House chief of staff and is now the secretary of the treasury; others commandeer boardrooms on Wall Street that were once closed to Jews.

Yet within this success there has been constant struggle in balancing the demands of a fully Jewish life and a place within the non-Jewish world. Living in their cloistered communities, Haredi Jews in certain respects have created an environment in which they can flourish through avoidance and rejection—of popular culture and the secular world. But for the Modern Orthodox, the challenges of modernity are unceasing. These Jews live in the present and engage it fully: Their children attend the nation’s best colleges and graduate schools, participate in athletic programs that often pose difficulties for Sabbath observance, are constantly surfing the Internet, and extensively interact with non-Jews.

And of course, owing to their engagement with the secular world, the Modern Orthodox have found themselves fully immersed in debates centered around the two great cultural fault lines of our generation: women’s rights and gay rights. Although many in the Modern Orthodox movement have tried to resist the pressure to afford women a more active role in synagogue services and have simply refused to acknowledge a role for homosexual couples within Orthodoxy, both of these walls are increasingly being breached.

The breach has been most pronounced in the case of women’s rights. Over the last decade, there has been a burgeoning of new “partnership” synagogues, in which men and women, divided by an Orthodox mechitza (a partition, so the sexes are separated when praying in synagogue), both participate as leaders in the services. And in the past few years, a prominent Orthodox rabbi, Avi Weiss, has begun to ordain women to serve as congregational rabbis. He has even established a women’s rabbinical college in New York. But the most recent indication that Modern Orthodoxy continues to bend to the zeitgeist comes from two of the most prominent Modern Orthodox high schools in New York City. These schools declared that girls are now permitted to wrap teffilin around their arms and foreheads when they say their morning prayers. Underscoring the tension inherent in being both “Modern” and “Orthodox,” rabbinic leaders at both schools made clear that even though such a practice was halachically (that is, legally) permissible, it was a communally “complicated” issue and would not be “recommended.”

Likewise, although Modern Orthodoxy has not followed Conservative and Reform Jews in approving gay marriage, a group of prominent Modern Orthodox rabbis issued a joint statement in 2010 urging members of their communities to accept homosexuals. And now gay couples are joining Modern Orthodox synagogues.

All of which raises the question: Are the Modern Orthodox in America really Orthodox?

As a matter of doctrine the fundamental tenet of Orthodox Judaism is the belief that on Mount Sinai, God transmitted to Moses both the written law (the Torah) and the oral law (the Talmud and certain other rabbinic texts). That is why Orthodox Judaism is generally resistant to changing interpretations of the law, except where there is some precedent for it in traditional law. To be sure, many Modern Orthodox rabbis and some of their congregants are steadfast in their faith and look to halacha to guide all aspects of their lives precisely because they believe it is the revealed word of God. But if unwavering acceptance of the Torah as divine is the precondition for Orthodoxy, then the term “Modern Orthodox” may well be a misnomer for many Jews who identify as Modern Orthodox. They might more accurately be described as Social Orthodox, with the emphasis on “Social.”

The Pew study offers insights that support this assessment. When compared with ultra-Orthodox Jews, Pew found that Modern Orthodox Jews are much less doctrinaire. Consider, for example, the question of faith. Among the ultra-Orthodox, 96 percent report that they believe in God with absolute certainty and 89 percent say that religion is very important in their lives. The percentage among Modern Orthodox Jews who feel equally certain in their faith is 77 percent, with a similar number reporting that religion is very important in their lives.

On the other hand, even though many Modern Orthodox Jews express a degree of doubt about their faith, in several important respects they are the most engaged part of the American Jewish community. For example, Modern Orthodox Jews are significantly more likely to be members of Jewish organizations (52 percent) than the ultra-Orthodox (33 percent), Conservative (27 percent), or Reform (20 percent). And when it comes to their attachment to Israel, the contrast is even greater, with 79 percent of Modern Orthodox Jews reporting that “caring about Israel” is an essential part of being Jewish, as compared with only 56 percent among the ultra-Orthodox, 58 percent among Conservatives, and 42 percent among Reform.

These survey results are reinforced by observing communities with great concentrations of Orthodox Jews. Two years ago, the UJA-Federation conducted a survey of the New York Jewish community, which, with nearly a half million Orthodox Jews, is the largest such community outside of Israel. Taking a more granular view than Pew did, the UJA subdivided the Orthodox into three categories: Hasidic, yeshivish, and Modern Orthodox. The first two, which account for two-thirds of New York’s Orthodox Jewish population, share several features in common and generally fit within the broad grouping of Haredim. They are very strict in their interpretations of Jewish law and live predominantly in concentrated communities often segregated from other Jews and non-Jewish communities. (A significant difference between Hasidic and yeshivish Jews is in education: The latter are more likely than the former to send their children to college.)

One of the major findings of the UJA study was that the Modern Orthodox (whom the UJA survey concluded were almost as distant from the Haredim as from the non-Orthodox) are more engaged in broad Jewish communal life than either the Haredim or the less observant and much more numerous Conservative and Reform communities. In totality, the Modern Orthodox are by far the most engaged group of American Jews. They reported greater participation in Jewish-community-center programs, more visits to museums or Jewish cultural events, more use of the Internet for Jewish purposes, along with their significantly greater attachment to the state of Israel. And while their birthrate is significantly lower than that of the Haredi community, it is double that of non-Orthodox Jews. The fact is that with an intermarriage rate among non-Orthodox Jews now higher than 70 percent, and with the ultra-Orthodox disengaging from the secular world as they cloister themselves in their self-contained communities, the Modern Orthodox may well be the best hope for an ongoing American Jewry that is part of the fabric of 21st-century American life—despite being only 3 percent of the total community.

What can we glean from all this data? That many self-identifying Modern Orthodox Jews, despite being more “Modern” than “Orthodox,” are living intensely Jewish lives. And precisely because of their dogma-averse approach to theology and to halacha, they are recapturing some of the creativity of rabbinic Judaism, which has ossified over time as, in the words of the Orthodox theologian Eliezer Berkovitz, many Orthodox Jews have become “Karaites of the Oral Law.” And this is the essence of Social Orthodoxy.

Social Orthodox Jews fully embrace Jewish culture and Jewish community. And they are committed to the survival of the Jewish people. Indeed, that is their raison d’être. Furthermore, because religious practice is an essential component of Jewish continuity, Social Orthodox Jews are observant—and not because they are trembling before God.

Some years after I first channeled the Jets to explain my Judaism, I had a conversation about religion with a devout Catholic friend. When I explained that I was an observant Jew and began each day by reciting the morning prayers but wasn’t really sure how God fit into my life, he was perplexed. When I admitted that these theological questions didn’t really occupy much of my attention and certainly weren’t particularly germane to my life as an observant Jew, he became agitated. And when I told him that I certainly wasn’t sure if Jewish law was divine or simply the result of two millennia of rabbinical interpretations, he threw up his hands and said: “How can you do everything you do, and live a life with so many restrictions and so many obligations, if you don’t even believe in God?”

I responded that there is a long tradition in Judaism of engaging first in religious practices and letting matters of faith come later. In the book of Exodus, after Moses has received the Commandments from God, he begins to instruct the Jewish people in the law; their immediate response is na’aseh v’nishma: “We will do first and understand afterwards.” I explained that while I understood that Catholicism, along with the other branches of Christianity, was essentially a religion based on the belief that Jesus is the son of God and the savior of humanity, Judaism is a complex blend of radical monotheism and peoplehood. In the Bible, the Jewish people are referred to not as a religious denomination, but as b’nai Yisrael, the children of Israel, the descendants of Jacob. Throughout history, Jews have referred to themselves as am Yisrael, the nation of Israel. The vast corpus of Jewish law, all 613 biblical commandments as well as the Oral Tradition, is a guide to how one lives a Jewish life as a member of the Jewish people.

And so for me, and I imagine for many others like me, the key to Jewish living is not our religious beliefs but our commitment to a set of practices and values that foster community and continuity. In this way, both Modern and Social Orthodoxy owe an ironic debt to Mordecai Kaplan, perhaps the most iconoclastic American rabbi and thinker of the 20th century. In the first decades of that century, Kaplan occupied pulpits in two of the most prominent Orthodox synagogues in New York City—Kehilath Jeshurun and the Jewish Center—and he was one of the founders of the Modern Orthodox “Young Israel” synagogue movement. He taught at the Jewish Theological Seminary, the center of Conservative Judaism. And then he made the radical move of creating an entirely new movement, Reconstructionism. In 1945, he was excommunicated by the Union of Orthodox Rabbis for what it deemed an unforgivable act of heresy—authoring a Prayer Book in which he eliminated every reference to the Jews as the “Chosen people.” His excommunication ceremony concluded with a public burning of the book.

Although Kaplan followed Jewish practices rigorously all his life (he died in 1983 at the age of 102), he was also a modernist who believed that modern science and archeology discredited faith in a divine supernatural being who acted in history, dishing out rewards and punishments. As he wrote in 1937 in The Meaning of God in Modern Jewish Religion, “the very notion that any text written hundreds of years ago, at a time when the social situation was radically different from what it is today, can give us clear and valuable guidance in deciding, ethically, issues that did not arise until recent times is utterly antagonistic to the modern evolutionary outlook.”

He was deeply influenced by Ahad Ha’am (1856–1927), the founder of Cultural Zionism and one of the people responsible for the rebirth of Hebrew as a spoken language. Like Ahad Ha’am, Kaplan also believed powerfully in Jewish peoplehood and culture. He dedicated himself to developing a Jewish theology that would reconcile reason and faith in the service of building Jewish community. As he explained in his most famous work, Judaism as a Civilization (1934), Judaism comprises a variety of what he called “sancta”: ethical principles, sacred texts, language, land, traditions, a unique calendar, and other indicia of community.

Kaplan’s Reconstructionist movement, from its inception, has remained a tiny minority within a minority. And yet, nearly 70 years after his excommunication, Kaplan’s perspective is surprisingly resonant within that of the Modern Orthodox world. As both the UJA and Pew data revealed, many Modern Orthodox Jews are more focused on living a Jewish life than they are on theology or a rigid set of rules. Modern Orthodox day schools teach evolution unapologetically, notwithstanding the literal text of Genesis. And they have begun to accommodate gay and lesbian students, notwithstanding the literal text of Leviticus, with one school even establishing a club as a forum for students to discuss matters of sexuality and identity. Notably, in Modern Orthodox day schools, much to the chagrin of their teachers, many students have taken to observing what they call “half shabbos”—the practice of going to synagogue and keeping the Sabbath, but using their iPhones and Blackberries to text on the Sabbath, despite the rabbinical prohibition on using electronics.

The Jewish Week, a New York paper, sent shock waves through the city’s Orthodox community a few years ago with an exposé reporting that texting on the Sabbath is becoming “an increasingly common ‘addiction’?” among Modern Orthodox teens. Rabbi Steven Burg, the international director of the Orthodox Union’s NCSY youth group, freely acknowledged in the article that “teens who text on Shabbat are an open secret in their schools and social circles.” And although two professors at Yeshiva University’s graduate school of education determined, in a survey hastily conducted the week following the publication of the article, that the percentage of Modern Orthodox teens who regularly text, surf the Internet, or use their cellphones on the Sabbath was only 15 percent, anecdotal evidence suggests it is much higher.

Yet despite such halachic foot-faults, these same Modern Orthodox Jewish teenagers and their families lead lives that are completely focused on Jewish values, ideals, and rituals. The adults attend synagogue regularly, participate in Torah and Talmud classes organized by their synagogues, donate significantly to Jewish communal organizations, and travel to Israel frequently. Their children study in dual-curriculum schools (often for 13 years); many then take a year off before college to study Talmud in Israel; and a great number spend their summers in Zionist Orthodox camps.

In perceiving the need to root American Judaism in something more tangible and rational than pure faith, Kaplan foresaw American Jewish practice that was focused primarily on community and secondarily on God. Many of his innovations, which still flourish today, gave structure to his reconstruction of Judaism. He instituted the practice of giving girls bat-mitzvahs (his daughter had the first one in 1922); after long resistance, Modern Orthodoxy has figured out ways to accommodate this ritual. Kaplan organized the first synagogue-as-community in America in 1916 when he founded the Jewish Center on the Upper West Side—the first “shul with a pool.” That innovation has been adopted widely in the Modern Orthodox community, with every synagogue now running a wide range of educational and social programs for adults and children.

In one critical respect, however, Kaplan missed the mark. Drawing on his background in sociology, Kaplan argued that with respect to organizing one’s life as a Jew, “belonging precedes behaving precedes believing.” By this he meant that the feeling of being a member of a group generally comes before adopting the group’s distinctive practices, which in turns comes before accepting the group’s core beliefs.

Because he sought to differentiate himself from traditional Orthodox Judaism, which centers on believing and behaving, Kaplan argued that the most elementary form of Jewish identification is belonging—what Reverend Stefan Jonasson has described as “the intuitive sense of kinship that binds a Jew to every other Jew in history and in the contemporary world.” Unquestionably, belonging is a powerful component of Jewish identity. After all, we constantly invoke our connection to our ancestors—Abraham, Isaac, and Jacob—and annually re-create the Exodus from Egypt, so we can feel that sense of belonging. Kaplan was wrong, however, in concluding that belonging precedes behaving. In fact, for many observant Jews, and certainly for Social Orthodox Jews, behaving is the first step. And it is actually the one necessary step. For it is through one’s behavior as a Jew—whether traveling to Israel as part of an organized tour, participating in a Passover Seder, attending a Sabbath meal, or just speaking Hebrew—that one gains the powerful feeling of belonging.

The best evidence that neither belonging nor believing promotes Jewish continuity as powerfully as behaving is found in the last part of the Pew study, where the authors describe their findings from interviews with several hundred individuals who are not Jewish under any recognized definition (they have no Jewish parent and have not converted), but who nevertheless claim to have an affinity for Judaism.

Ironically, these non-Jews who claim to belong to the Jewish community (and Pew suggests that more than a million individuals fit into this category) tend to be more God-centered in their faith (at least when measured by their faith in God) than the rest of the Jewish community—and nearly a third of this group root their Jewishness in the fact that Jesus was Jewish. Not surprisingly, the Pew study found that this group (which only rarely engages in Jewish rituals) is far less involved in Jewish communal life (whether synagogue attendance or membership in Jewish organizations) than those of any denomination who are born into Jewish homes or convert to Judaism.

In short, they do not behave, so they do not really belong—whatever it is that they believe.

As for me: I start my day each morning by donning my tefillin before heading to my office at a law firm. I eat out in restaurants several times a month only to pass up 90 percent of the menu in favor of vegetarian fare because I keep kosher. I occasionally find myself stuck in cities on a Friday far from home because I cannot travel back to New York City in time for the arrival of the Sabbath. I go to synagogue each week and celebrate all the Jewish holidays. My children attend a Modern Orthodox day school, and my college-age daughter served as a soldier in the Israeli army. And I am proud to be a Zionist. Unless one were to look very carefully, I would appear to be the very model of an Orthodox Jew, albeit a modern one. But I also pick and choose from the menu of Jewish rituals without fear of divine retribution. And I root my identity much more in Jewish culture, history, and nationality than in faith and commandments. I am a Social Orthodox Jew, and I am not alone.

I once asked my father why he studies Jewish texts and practices Jewish rituals so rigorously. I knew he was agnostic when it came to matters of faith. He told me that he observes the Commandments because that is what connects him to Jews across continents and centuries. He said that he views halacha as a compass, and that every Jew, even if he or she chooses to take some detours along the way, should know which direction is true north.

Whether such a cultural tradition can be sufficiently transmitted to the next generation is a fair question. Certainly, a neat theological package provides parents with a more direct message to convey to their children. Yet there is also an authenticity in a dynamic Judaism that recognizes its origins as a national identity. As Leon Roth, the first professor of philosophy at the Hebrew University observed, dogmalessness is “the only dogma in Judaism.”

So it is with many Social Orthodox Jews. We generally choose to head north, where halacha dictates. But we live in the modern world, and occasionally we explore the pathways around the edges of halacha. Much more important to us than theology, however, is maintaining the continuity of the Jewish people.

What Kaplan called “civilization” and Ahad Ha’am called a “national culture” is what moves many of us. We behave as Jews so we can belong as Jews. Some of us may even come to believe. The key, however, is that we live Jewish lives so we will not be disconnected, and we will never be alone.