As someone who has worked to build Jewish organizations in various parts of the world, I have met my share of wealthy people and philanthropists. Some are immensely generous, while others like to keep what’s in their pockets. Some treat you with immense respect, while others evince the arrogance that may accompany wealth. Some are passionate about the future of the Jewish people, while others want their names on non-Jewish walls.But the one donor who towers over them all is birthright co-founder and mega-philanthropist Michael Steinhardt, who today celebrates his 70th birthday. I write this tribute to him not as a friend who has known him for 15 years, or as someone who has partnered with him on projects in Oxford and New York. Rather, I write as a Jew who stands in awe of an unrepentant atheist with an unsurpassed love of the Jewish people.The writer is the international best-selling author of 24 books, most recently Renewal, and the founder of This World: The Values Network, which brings Jewish values to the mainstream culture. Follow him on Twitter @RabbiShmuley.Michael is a man of profound contradictions.Corner him in his office about God and he will growl about never foregoing his atheism. Yet no donor has spent more to develop American Jewish day-schools or foster Jewish identity.Argue with him that only Jewish ritual observance can guarantee Jewish continuity and he will roll his eyes about Orthodox propaganda.Yet few philanthropists have pumped more money into Hillel, Jewish education and national Shabbat programs, like offering birthright alumni grants to host Friday-night dinners so young lives can be illuminated by ancient tradition.Tell him that without the Jewish religion, our people are doomed to assimilation and he will use his razor-sharp analytical skills to mind-slap you with demographic data about Jewish pride resulting from secular, rather than religious achievements. Yet no man has exposed more young Jews to Judaism than Michael (and his partner Charles Bronfman) through his vision for birthright that has brought more than a quarter million, mostly assimilated young Jews to Israel.A YEAR ago I lead a birthright trip for Mayanot, the Jerusalem educational institution founded by Rabbi Shlomo Gestetner. I asked my group of 50 to raise their hands if they had had a bar or bat mitzva. When only six hands went up, we quickly organized a moving celebration at the Kotel. The men put on tefillin and the women lit Shabbat candles for the very first time.I called Michael in New York to needle him.“Because of you, young Jews are keeping more mitzvot than all the world’s rabbis combined.You’re losing your own battle to promote your secular, common Judaism.”He chuckled and then quickly returned to his usual grumblings about the Orthodox.But there is an even more fundamental reason that Jews the world over should salute Steinhardt. Jews did not choose to become bankers. There is no commandment in the Torah that says, “Thou shall profit in thy investments.”We were traditionally an agricultural community, but were prohibited from owning land by our European Christian overlords. Of necessity we turned to banking.Many accusations ensued, beginning with the Rothschilds, who were unfairly accused of profiting from both sides during the Napoleonic wars, and culminating in the recent collapse of Wall Street banks, a disproportionately large number of which had Jewish names and Jewish heads.People who are not our friends started making correlations between Jews and banking greed.But standing as a bulwark against any such accusation is Steinhardt, who largely founded the hedge-fund industry but hung up his spurs at the height of his success to focus on the well-being of his people. When I asked him why, he told me: “I was afraid that on my tombstone it would say ‘money manager.’” For Michael the accumulation of wealth as an end in itself is a pathetic form of compensation for an inner insecurity. Wall Street has meaning when it pays for birthright kids to see the Western Wall. Investments have a purpose when they help poor Israeli families afford their rent, rather than when they facilitate more champagne-swilling in the Hamptons.Other hedge-fund giants like George Soros ignore the Jewish community, seeking a global presence instead. But while he supports myriad non-Jewish causes, Steinhardt unashamedly celebrates his love of Israel and the Jewish people.I WOULD be remiss if I did not confess a personal reason for writing this column. No one who works outside the nonprofit world can appreciate just how awful raising money can be.I hate it. Having to ask people for money to support your programs is, for me, a degrading and humiliating purgatory.But Michael has always been a friend rather than a supporter, kibbitzing, arguing and ultimately tormenting me with love. I have no bigger critic.“How insecure are you, Shmuley, that you have to hang out with damaged celebrities?” (OK, you’ve got my attention). “You’re unfocused and all over the place.” (Getting warmer). “When are you going to stop believing that you influence the Jewish world through non-Jews?” (Bingo!) But then it’s your turn. “My God, Michael.I’m getting depressed just listening to you.”Now you have his attention. Michael despises brown-nosers and comes to life when you hit back. A word of caution. If you’re single, stay away. His foremost passion is matchmaking, with his sole criteria for male-female compatibility being that each possess a pulse.But for all his grouchiness, you will never find a more loyal friend or wise adviser – one who will stand by you no matter the controversy.I was therefore heartsick to hear Michael announce at his 70th birthday party that he plans to retire from Jewish communal life next year and move on to the next chapter. Doing so would impoverish Jewry of one of its most innovative rebels and thought-provoking irritants.And Jewish youth would lose its most stalwart advocate.Happy birthday, Michael! Now cut the nonsense. If you promise not to abandon us, we promise to give as good as we get.