Twenty years ago on Tuesday, I awoke early in Oxford because I was taking a non-Jewish student president of our L’Chaim Society named Cory Booker to Israel for the first time. I was packed and getting dressed when the phone rang. It was my father calling from Jerusalem.“I don’t think you’re coming to Israel today,” he said.“Why not?” I asked.“Israel Radio just announced the passing of the Lubavitcher Rebbe.”The irony of hearing the shocking news about the loss of a father figure from my actual father was not lost on me, but I had no time to mourn. I dashed to Heathrow airport to try and make the funeral in New York. Luckily, I was already packed.I called Cory, who would later become Senator from New Jersey, where I live, and said, “Cory, the Rebbe just died. I can’t go to Israel with you. But I’ll arrange for someone to escort you,” which I did. Knowing my close relationship with the Rebbe, he understood.The airline miraculously had a Jewish check-in clerk who somehow got me and about 30 other Chabad rabbis on a flight that would get us into New York on time. It was a miserable flight, with so many memories passing through my mind. Arriving at JFK amid a steady downpour, I dashed to Crown Heights and made my way into the Rebbe’s office, where I saw the Rebbe cloaked in a prayer shawl. Governor Mario Cuomo was there, looking somber, his head bowed. Few cried and no-one spoke.Downstairs in the Rebbe’s synagogue thousands were dancing in the belief that this passing was a stage in the Rebbe’s revelation as messiah. The celebration sickened me and I went back upstairs where they took the Rebbe’s body out in the wooden remains of his prayer stand. A wall of sound hit me, almost knocking me over – the cry of 20,000 women wailing upon seeing the Rebbe in the makeshift coffin. I ran behind the body, losing my hat, tearing my suit, and struggling not to be trampled. The pushing became so dangerous that they put the Rebbe in an ambulance and slowly began to drive. I ran alongside, increasing my speed as they accelerated, and sprinted until I could run no longer. It was only then that, as I stopped, gasping for air, I began to cry. If the Rebbe were still alive he would have kept me running. But who would inspire me now? Approximately 50,000 people attended the funeral; far smaller than the funerals of other great rabbis, such as Moshe Feinstein who had died just a few years earlier, and it was mostly Chabad hassidim who attended.The twentieth anniversary of the Rebbe’s passing is being accompanied by the portrayal of the Rebbe as the founder of “Judaism with a smile.” He was vastly popular, opened more Jewish educational centers than any Jewish leader in history, and helped to turn the tide of assimilation after the devastating losses of the Holocaust. But this is not the whole story, and it sanitizes the Rebbe’s legacy.In truth, the Rebbe was a revolutionary. His Judaism was warm but it was also controversial and intentionally divisive. The Rebbe forced you to take a stand. He played on your conscience and made you choose. Would you practice a convenient Judaism that focused only on your own spiritual development or would you turn your personal home into a communal center, inviting in the less observant, the neglected? Would you practice Judaism in private or would you be identifiably Jewish, with a kippah, in the street? Would you make peace with the world’s flaws or would you clamor for a messianic, more perfect world? Chabad today is mainstream and, as such, has lost some of its revolutionary ardor. It is inconvenient to rock the boat when you are the boat. Hence, we hear little today about the Rebbe’s intractable opposition on territorial concessions in Israel. Gone is the Rebbe’s battle cry that Israel’s retreat would embolden its enemies and invite further attack. We hear little about the Rebbe’s insistence that Judaism had a message for non-Jews amid its call for a universal ethical covenant.When I made Cory the president of the L’Chaim Society at Oxford University and included thousands of non-Jewish members at our activities, it famously cost me my job as head of Chabad at Oxford. Today, of course, various Chabad rabbis to whom I introduced Cory compete to publicly proclaim their influence on the Senator and their inclusion at our prayers at the Rebbe’s grave. But outreach to non-Jews who are not public officials remains highly controversial.And we hear little about the Rebbe’s constant discussion about messianism – not his personal candidacy for messiahship, which he found vulgar and strongly rejected – but in people being fed up with a flawed, murderous, evil world and demanding better from God. The Rebbe’s thundering cry to God – always done in public: “Ad Mosai?” How much longer? objecting to the Creator allowing the indiscriminate murder of Jews in terror attacks has today been replaced with a silent, religious resignation to the fact that God is always just, even as the long-promised messiah still tarries. Today the Rebbe is popular. But his funeral told a more honest story. He never pursued popularity and there were many who boycotted his message. He never feared controversy. It was influence, rather than numbers, that mattered. His mission was to make Jews uncomfortable with a materially-driven life and he never intended for his movement to simply open centers the world over so that Jews could get kosher meals on vacation in the Caribbean or doing business in the Far East.That Chabad can provide these essential amenities, thereby ensuring Jewish observance in the most remote places, is vital, but of secondary importance. The Chabad House’s principal purpose is to spread the influence of the Torah and make the Jewish people a light unto the nations.The Rebbe loved all Jews and he loved all people. He despised the squandering of human potential and demanded even more of his followers when they believed they had nothing left to give. He always sought to be inspirational but was prepared to be an irritant.At the end of the Bible Moses ascends to his burial at Mount Nebo – unknown to us till this day – alone by God’s command. There was none to say the kaddish for him, none to offer a eulogy, no honor guard and no 21-gun salute. His legacy was not that of the popular leader who was lauded by the people, but rather of the law-giver who pushed his people to aspire to holiness, often against their will.The Rebbe, who followed in Moses’ footsteps as one of the great Jewish leaders of all time, courageously trailblazed the same lonely path. Will we run alongside him? The author is founder of This World: The Values Network, the foremost organization influencing politics, media and culture with Jewish values. He has just published Kosher Lust: Love is Not the Answer. Follow him on Twitter @ RabbiShmuley.