Yaakov Birnbaum, the man who launched the Soviet Jewry grassroots movement that retrieved three million lost Jews, and who died last week at age 87, was my first rebbe, my first spiritual teacher.

I met him sometime in 1965. He was the elder visionary, all of 38 years old, and I was his disciple, age 12. Yaakov, a big, bold, passionate man with a Van Dyke and a Russian fur hat, spoke a language of redemption that I’d never heard before and that Jews in the years after the Shoah evoked only in bitter irony. Yaakov insisted that, even after decades of enforced assimilation, Soviet Jews weren’t lost to the Jewish people, and that the “Jews of Silence,” as they were known then, would one day publicly reclaim their Jewish identity.

He not only insisted that it was possible to save Soviet Jewry: He had a plan. The Soviet Union’s economic plight, he predicted, would cause it turn to the U.S. for aid, and that would allow Congress to pressure the Kremlin to open the gates to Jewish emigration.

The effort to free Soviet Jews, Yaakov predicted when he founded the Soviet Jewry movement in 1964, would take 25 years.

Yaakov’s grand predictions all came true. The Kremlin did in fact seek trade credits from the U.S., and the Jackson Amendment placed the Soviet Jewry issue at the heart of the Soviet-American relationship. And when the gates opened in 1989, it was 25 years to the founding of the Soviet Jewry movement.

Yaakov’s prophetic intuition came from a total identification with the Jewish people. I had never met someone more authentically Jewish, and by that I mean that he had a connection with all parts of the Jewish people. Nothing Jewish was alien to him. He was a Yiddishist and a lover of Sephardi culture, at home in a chasidic shteibel and in an egalitarian minyan. After the Shoah, Yaakov, who’d fled Nazi Germany as a boy, volunteered to work with survivors in the displaced persons camps. And when the great Jewish communities of North Africa were coming undone in the 1950s, Yaakov went to Morocco, and then to France, to work with young Sephardim.

Jewish eclecticism was an inheritance from his grandfather, Nathan Birnbaum, who was, at different stages of his life, a Zionist leader (he coined the term “Zionism”), an activist in a spiritual movement of what today might be called Jewish renewal, and a founder of the ultra-Orthodox Agudath Yisrael. Grandfather Nathan’s wanderings across the Jewish spectrum were reconciled in Yaakov, who accommodated rival Jewish camps in his own being. A klal Yisrael Jew, as he liked to call himself, a Jew who identitied with the totality of his people.

Et tsara hi l’Yaakov: It is a time of trouble for Jacob. Yaakov took those words from the Torah as a personal imperative to help Jews wherever the trouble was coming from next.

I once attended a meeting with him of the umbrella group created by Jewish establishment organizations to support Soviet Jewry. It was the fall of 1970, and a group of Soviet Jews had recently been arrested for attempting to a hijack a plane to Israel. Though refuseniks had sent a letter addressed to world Jewry warning that a show trial was being prepared, establishment groups were slow to respond. Yaakov pounded on the table and shouted, “Jews! A trial is being prepared!”

There was embarrassed silence in the room. There he goes again, you could almost hear people thinking, this nudnik who thinks he’s the only one who cares about the Jewish people. But Yaakov couldn’t bear complacency. He felt as if he himself were about to stand trial.

When Yaakov first launched the protest movement, much of the Jewish community regarded him as a fantasist, if not a dangerous meddler who would only “make things worse.” The organization that Yaakov founded — the Student Struggle for Soviet Jewry (SSSJ) — was always broke. The “movement” was a few dozen kids in New York, along with a handful of independent groups around the country that later banded together to form the Union of Councils for Soviet Jewry. The indispensible coordinator was Glenn Richter, who ran the SSSJ office and organized the demonstrations and kept in active contact with other grassroots groups and with refuseniks in the Soviet Union.

The refuseniks emerged in response to the Six-Day War. Suddenly the Jews of Silence were leading the movement — from within the Soviet Union. Yaakov and Glenn insisted that American Jews learn the name of each refusenik. At one demonstration in a nearly-empty Dag Hammarskjold Plaza near the UN, Yaakov led us in a chant for a Riga Jewish woman arrested a week before her wedding: “Free Ruth Alexandrovich! Free Ruth Alexandrovich!” The clumsiness of the chant didn’t matter: Yaakov wanted Ruth to become a part of our being.

Yaakov’s vision — that the protest movement would be led ultimately not by a small group of students but by the organized Jewish community — was fulfilled following the Leningrad Trial of late 1970, when Jewish establishment organizations committed their resources to a sustained campaign. The Greater New York Conference for Soviet Jewry initiated the annual Solidarity Day demonstrations, which, for the first time, brought hundreds of thousands into the streets. The Conference was led by Malcolm Hoenlein, an early SSSJ activist.

It’s not surprising that Yaakov’s soul departed just before Passover — and as we are about to mark the 50th anniversary of his founding of the Soviet Jewry movement. Yaakov was the first to insist on the slogan “Let my people go” — that the aim of the protest movement wasn’t only the betterment of Jewish life in the Soviet Union but mass emigration, which in the 1960s seemed inconceivable. Our early demonstrations were led by a mural showing split waters with the words, “As the Red Sea Parted for the Israelites, So Will the Iron Curtain Divide for Soviet Jewry.”

The movement Yaakov began transformed the Jewish world beyond recognition. Its impact on Jewish history goes beyond the rescue of Soviet Jewry.

The Soviet aliyah of the early 1990s helped transform Israel into an economic power. And through the Soviet Jewry protest movement, American Jewry became a self-confident community able to defend Jewish interests in the public space.

The most creative rabbis emerged from Yaakov’s circle: Shlomo Carlebach and Yitz Greenberg and Art Green and Avi Weiss and Shlomo Riskin — rabbis who reimagined American Jewish life. That too was part of Yaakov’s prophetic intuition: In saving Soviet Jewry, a revitalized American Jewry would save itself.

And all these years Yaakov lived in obscurity, with his beloved Freda, in the same apartment on Cabrini Boulevard in Washington Heights, from which he ran the movement in its early days. With a few precious exceptions, he received little honor from the Jewish community. Gratitude isn’t always our strong point.

Maybe the best way to say thank you is to honor Yaakov’s last campaign — to establish a Day of Liberation for Soviet Jewry. At a time of demoralization and divisiveness within the Jewish people, Soviet Jewry Liberation Day would remind us to never lose faith in the possibility of redemption.

Yossi Klein Halevi is a senior fellow of the Shalom Hartman Institute in Jerusalem. His book, “Like Dreamers: The Story of the Israeli Paratroopers Who Reunited Jerusalem and Divided a Nation,” won the Jewish Book Council’s Jewish Book of the Year award.