Late in the spring of 2010, just about the time of his yahrzeit, Sammy Davis Jr.’s menorah went up for auction. It was a silver menorah, given to Davis in 1965 by the Women’s Division of the Jewish Federation in New York. The owner, a collector of Judaica, had set a bidding floor of $10,000. Yet when the day of the auction arrived, only two potential buyers pursued it, and the highest offer came in at $8,500. So the menorah headed back into a safe-deposit box, and the whole episode took on a pathetic cast.

Part of me could understand why the menorah went unwanted. At 55, I’m old enough to remember Sammy Davis Jr. as the remnant of a previous generation and its outmoded notions of cool. I experienced Davis as the token black in the Rat Pack, almost palpably groveling for acceptance, laughing too loudly at some Sinatra joke at his expense. I experienced Davis trying to reinvent himself for the counterculture era as a guest star on “Mod Squad.” I experienced Davis, amid the Watergate meltdown, hugging Richard Nixon. His style seemed as dated as his conked hair.

Another part of me, though, found the story of that scorned menorah heartbreakingly poignant. It made me think of Sammy Davis Jr. as one of those prophets without honor in his own land. A black man born to Baptist and Catholic parents, Davis converted to Judaism in 1954. The white woman whom he married, Swedish actress May Britt, converted before they wed in 1960. This racially mixed couple of two former Christians produced a biracial Jewish child several years later.

In all those ways, then, Davis was pointing the path toward a different kind of Jewish identity. He served as an object example of religion rather than ancestry, observance rather than upbringing, being the portal into Jewishness. Only now, more than a half-century since his conversion and marriage, are we seeing the full flowering of this phenomenon. It has profoundly altered Jews’ traditional views of who is in and who is out, who is Us and who is the Other.

For two millennia of the diaspora, Jews hardly needed to ponder such questions. Persecution and oppression from the outside walled us in together. Interfaith marriage was a rare anathema. We defended ourselves in part with linguistic weapons, words like goy and shiksa and shaygetz and schvartze that turned the bigotry we felt back against our tormentors.

In the American Jewish context, one numerically dominated by Ashkenazi Jews from Eastern Europe, this meant that one was a Jew not only by the biological requirement of birth but by the lifelong knowledge of a set of folkways. Eating chopped liver, voting Democratic, knowing some Yiddish, getting Woody Allen jokes, losing relatives in the Holocaust, being a Zionist — these experiences amounted to a kind of secret handshake that only fellow members of the tribe could share.

A famous advertising campaign in the 1960s showed photos of different New Yorkers, black and Chinese and so forth, each biting into a piece of rye bread. “You don’t have to be Jewish to love Levy’s,” went the slogan. That was half true at best. Jews had indeed impregnated America with elements of their culture, from bagels to Mel Brooks, but we all knew privately that not even the best-intended goyim could truly belong. You had to have grown up with this stuff; it had to be in your kishkes.

Even so, and kind of amazingly, this secular/cultural definition of Jewish identity was perceived as being, for lack of a better word, liberal. The reason is that the alternative definition, one based in religious practice, was so easy to dismiss as conservative. What could be more exclusionary, after all, then all those rules and regulations and mitzvot? What was more retrograde than a Jewish life based on a never-ending tzitzit check?

But what if we were wrong and Sammy Davis Jr. was right? What if secular/cultural Jewish identity is the exclusionary sort and religious Jewish identity is the radically inclusive one? I am not arguing a simple premise, I realize, because each branch of Judaism has its own separate standards for conversion, and the Chief Rabbinate in Israel refuses to recognize the legitimacy of even many Orthodox conversions. The fractured parliamentary politics of Israel, with haredi parties often in governing coalitions, holds the risk of alienating and disenfranchising the vast majority of American Jews.

Yet Israel with its Ethiopians and Indians, its blue-eyed blond Europeans, its white-bread Middle American expats simultaneously manifests the radical inclusiveness of religious Jewishness. Study, learn, practice, observe, and it doesn’t matter if your grandmother was from Addis Ababa instead of Odessa. It doesn’t matter if you hate gefilte fish. It doesn’t matter if Yiddish sounds like gibberish and you don’t get Borscht Belt punchlines. Those things are trappings, not essence.

Certainly, risks and challenges accompany Judaic inclusiveness. When Jewish identity no longer presupposes a shared history, religion can become uncoupled from peoplehood. Our era of spiritual seeking lets people choose not only belief systems but systems of belief; the underlying message is that every person has the right to be a congregation of one. Even among born Jews, we already have enough problems with disaffection from Israel or outright anti-Zionism.

A few months ago, I happened to read an article in The Jewish Week about a black Jamaican immigrant who had converted to Judaism and become a Lubavitcher chasid. He was killed in the robbery of a Brooklyn liquor store. A contingent of Chabad rabbis brought his body back to Jamaica for burial. It seemed to me like the most luminous response to the terrible tensions between blacks and Jews in Crown Heights that resulted in the riots 20 years ago this August.

The conversions of previous generations were gun-to-the-head affairs, the requirement Jewish parents demanded of any gentile about to marry their child. That sort of conversion has grown less common; our multicultural age with its paeans to diversity finds little purpose in compelling such obeisance. And that’s just as well. We as Jews have been too often the objects of coerced conversions to want to instigate them.

Instead of a closed door, today we have a revolving door. As born Jews exit by interfaith marriage or waning attachment, Jews-by-choice enter in the Sammy Davis Jr. way. He died a generation too soon to see the American Jewish community become 7 percent non-white, according to several studies. He did not live to see adoption create a whole subset of Chinese and Latino Jewish children of white Jewish parents. He was decades in the grave when the black first lady had a black rabbi for a cousin.

In most ways, I bemoan the disproportionate role that Chanukah plays in American Jewish life. It seems clear to me — hardly an original insight — that we put so much emphasis on Chanukah as a way of reconciling our religious celebrations with those of the Christian calendar. We had to match Christmas or go broke trying. Next Chanukah, though, I’ll think of lighting Sammy Davis Jr.’s menorah, the one whose illumination symbolizes a modern kind of miracle.

Samuel G. Freedman is the author of six books, including “Jew vs. Jew: The Struggle for the Soul of American Jewry.” He is a journalism professor at Columbia University and a religion columnist for The New York Times.