Bridge building is notoriously challenging for architects and civil engineers. The structures have to bear enormous weight and withstand weather, fire and unpredictable natural disasters. Construction is often treacherous. Precise planning is necessary, but not always sufficient. When successful, a bridge isn't only a passageway but an object of beauty.

Building bridges across the enormous chasms that separate practitioners of different religions fraught with historical and ideological conflicts is also thorny. No one knew that better than the renowned religious bridge builder Rabbi Yehiel Eckstein, whose life was tragically ended last week by a heart attack. His efforts were buffeted by tempests at every turn, but persistence and good will usually prevailed and many of those who vilified him came to regret their attitude. Would that the Jewish world that first maligned him could have earlier shown the foresight to appreciate the vista of what he was about to accomplish.

Like many persons involved in the Jewish nonprofit world, I met Eckstein many times and like most Israelis, I enjoyed his trademark American-accented fundraising radio spots for the organization he founded in 1983, The International Fellowship of Christians and Jews, called Keren Yedidut in Hebrew. His fascinating authorized biography, The Bridge Builder: The Life and Continuing Legacy of Rabbi Yechiel Eckstein, was written in 2015 by Israeli-American author Ze'ev Chafetz.

The sobriquet "Bridge Builder" also resonates with a favorite song that he himself performed in Israel's 1973 Hassidic Song Festival based on the aphorism of Rabbi Chaim Nachman of Breslav: "The world is a narrow bridge, and the essence is to not be afraid."

But Eckstein's bridge was wide, taking him to help Jews in at least 58 countries, in addition to Israel. He also traveled to China to work for the freedom of imprisoned Christian pastors.

On the shocking news of his death, praise and appreciation flowed in from around the world, stories documenting the breadth of his impact. Under his leadership, the IFCJ supported Jews from the former Soviet Union, from Ethiopia and Northern India.

His outreach began when Eckstein, 25 and recently married, was hired by the American Anti-Defamation League (ADL). He was dispatched to Chicago to report on and work against bigotry, just as the neo-Nazis in Skokie, a township north of Chicago, were planning to march in Nazi regalia. The neo-Nazi rights to free speech became a much-debated issue in the United States. Whether or not to take part in a counter-demonstration was a much-debated issue within the Jewish community.

Eckstein discovered previously unrecognized allies for the Jews among the Evangelical Christians of Chicago. As a rabbinical student, he had been inspired by the social activism of Rabbi Abraham Joshua Heshel, who wasn't afraid to literally link arms with Christian leaders, most famously with Martin Luther King in Selma, Alabama.

In Chicago, Eckstein was the first Jew many of the Evangelical pastors had ever met and they were willing, even eager, to support Jews, Israel and Soviet Jewry. When the ADL wasn't enthusiastic about his new recruits, Eckstein started his own organization, Holyland Fellowship of Christians and Jews, which eventually became the IFCJ. At the beginning, Eckstein needed to work part-time as a rabbi and part-time as a wedding singer to pay the family bills.

Mainstream Jewry, rightly or not, was mistrustful and denigrating. Chafetz's biography of Eckstein opens with "the worst day of Eckstein's life" – his daughter's bat mitzvah, when Eckstein was forced to step down from the bimah of an Orthodox synagogue. But even at that moment of humiliation, he had faith in rightness of his vision, a previously unimagined alliance of Zionist Christians and Jews.

Television advertisements brought a landslide of Christian checks, mostly modest donations from men and women who wanted to support Jews and their biblically predicted return to Israel.

Reactions among Jews included embarrassment that Christians needed to be solicited to feed hungry Jews, suspicion of the donors' objectives and even accusations of conspiracies to take over Jewish institutions. But evidence of the good deeds with no strings attached, the volume of the help to the needy and Eckstein's Orthodoxy won over most objectors. Still, the sting of the accusations of underlying nefarious agendas and lack of full recognition were never completely gone, sadly recalled by family members in their graveside eulogies.

Eckstein's contribution to our world goes beyond the money, although the 1.6 billion dollars that ICJF has donated have impacted so many lives for the better. In a world in which antisemitism is metastasizing across the tissues of extremes to the centers of democracies, our ties with pro-Israel Christians are more important than ever. Fundraisers have understood from the time of the Bible that being a part of an idealistic endeavor goes beyond lip service and requires contribution. By providing the opportunity to Christians to join in helping and building, Eckstein strengthened invaluable ties of mutual respect and friendship. Where would we be without the decades of his pioneering work?

The last time I saw Eckstein was a month ago when he came to Hadassah University Medical Center on Jerusalem's Mount Scopus, one of the many hospitals that ICJF supports. He dedicated a robotic walking machine called Lokomat, donated by ICJW. Demonstrating the machine was 21-year old Dvir Teitelbaum, who lost his ability to walk while serving in the IDF. Teitelbaum was serving on Israel's northern border when he couldn't shake his tiredness. Within a few days Teielbaum could barely move. He was diagnosed with Guillain-Barre Syndrome, a rare disorder that initially causes muscle weakness and then paralysis as the immune system attacks the nervous system. The sophisticated machine compensates for what the muscles can no longer do, a computer increasing weight as strength is regained. Eckstein cheered Teitelbaum, who is, thanks to the machine, beginning to walk again. In his rich baritone, the rabbi reached for his guitar and serenaded the staff of therapists and visitors with "On the Summit of Mount Scopus."

Later, Eckstein went down to a new construction site in the parking lot of the hospital, bent over and shoveled dirt to help lay the cornerstone of the new rehabilitation center that will serve soldiers and civilians in Jerusalem. With his usual good humor, he pointed out that his last name, Eckstein, means "cornerstone." Then he began singing again, this time a beloved line from Hallel, the song of praise.

"Even maasu habonim…" The stone the builders rejected has become the main cornerstone."

May his memory be for a blessing and inspiration.