It's the day after Madonna's second concert at Hayarkon Park, and Karen Berg was up late the night before at the end-of-tour after party at a swanky club at the Tel Aviv Port mingling with the likes of Natalie Portman, Sasha Baron Cohen and Bar Rafaeli. But by mid-morning, the Orthodox New York native in her mid-60s was already on her way to an army base near Karnei Shomron to attend a ceremony dedicating 40 air conditioners. They were a gift to the IDF from the Kabbalah Center, an organization that she cofounded in 1973 with her husband, Rabbi Philip Berg. Today the Bergs' multimillion-dollar empire encompasses more than 50 study centers around the world, has introduced and nurtured A-list students like the Material Girl, Demi Moore, Ashton Kutcher and Donna Karan, has transformed Kabbalah into a household name - much to the chagrin of the Orthodox establishment - and along the way, has made the Bergs very wealthy. Now, mid-afternoon, she's relaxing at a spacious villa north of Netanya, the lunch guest of a young couple who study at the Tel Aviv's Kabbalah Center. While the chef begins grilling steak by the pool and other lunch guests arrive - including her son Michael and celebrities by association like Gwyneth Paltrow's sister - Berg recounts her journey from answering phones in Queens to having Madonna's cell number on speed dial, and explains why Kabbalah, for so long the closed secretive domain of the pious and learned, has become a populist answer in the quest for spirituality. "My background was totally secular. On Yom Kippur, our family would close its business - because it wasn't nice to work on Yom Kippur - and we'd have a feast. That's how much we knew about religion," she said. "It was interesting because growing up, I knew instinctively that there was something beyond that which we can see and feel. As a young girl, I started looking into things like Zen Buddhism and the rest of those things to try to find something that spoke to me," she added as another lunch guest at the home, Madonna's teacher Eitan Yardeni, poured glasses of wine. Berg's introduction to Kabbalah took place when, according to published accounts, she ran into Philip Berg more than a decade after she had once worked for him as a secretary when he was an insurance salesman in the 1950s and she was a teenager. Now, in the late 1960s, Berg (born Shraga Gruberger), who had been ordained before going into insurance, was learning Kabbalah. "He told me that he had left the business world and everything pertaining to it and was studying Kabbalah with a teacher. I said, 'Kabbalah, wow!'" recalled Berg. "I told him from what I'd read, it seems that Kabbalah was the core root of all spirituality. Then I said to the Rav [the name by which she regularly refers to her husband], I would really love to learn about it, how about you teach me and I work for you for free? That was the beginning of a 35-year relationship with the Rav." That relationship quickly evolved into a romance, despite the fact that the rabbi was married, and Berg herself was divorced with two children. By 1971, the Bergs were married and on their way to Israel. For 12 years, they lived in Tel Aviv and attempted to teach Kabbalah to the masses. "WHEN I started to learn, I said to my husband, if I can learn it, then we need to teach it to the world," said Berg. "He said, 'It's impossible, we'll get murdered, certainly by the Orthodox community, because nobody had ever done that before.' "But I had this crazy dream that we would go to Israel and start a center and teach men and women. We started teaching in English at the ZOA House in Tel Aviv. I think this was the first place that Kabbalah was taught to men and women together." By 1983, the Rav had devised a plan to print the entire Zohar in English and distribute it in the US, and wanted to send some of his students overseas to hawk it. But Berg saw it differently. "I told him that I didn't think that's the way to do it. We should go to America, sit in one place and people will come to us. If we really have the goods, people will want it," she said. So despite having two young children of their own, Michael and Yehuda, the Bergs returned to Queens. The rest, as they say, is history, and by the mid-1990s, they had set up shop on Robertson Boulevard in Los Angeles, where the first Kabbalah Center was opened and today thrives with hundreds of students and scholars. "We bought the Los Angeles center when we didn't have two quarters to put together, let alone $2.5 million," recalled Berg. "The Rav said, 'How are we going to do this?' And I answered, if it's supposed to happen, it will." It was that combination of faith and chutzpah that enabled the Bergs to buck vociferous opposition from Orthodox institutions that saw what they were doing as blasphemy. "We created something that never existed before," said Berg. "When we started the Kabbalah Center, the rabbis, of course, hated us. We were in uncharted territory. We were teaching something that had only been taught to men over 40 who were married." "We've always clarified that there are two parts to Kabbalah. For the sitrei Torah - the secrets of the Torah - indeed there a number of prerequisites that most people do not meet. But the other part of Kabbalah is like a child who seeks to learn a taste of the Torah. A person may be asking himself why is he here on earth, what do we bring to this life, why do we have the children we have? And Kabbalah can help answer those questions. "The Kabbalah teaches that everything that happens to us in our lives is grooming us to be the kind of person we need to be in order to complete what we call our process, and by doing so, getting closer to the energy." Berg answers critics who call the Kabbalah Center's version of Kabbalah a "pop" watered-down version to make it more palatable with a resounding, "It's true!" "At the beginning, when you come to your first classes, you don't become a master. Like when you learn yoga, you don't become a yogi right away," said Berg, who written several books based on Kabbalah including God Wears Lipstick: Kabbalah for Women. "We believe that the first classes of Kabbalah that we teach are a gateway. And that gate should be open to everyone to walk through. But the difference in how we open that gate is that we don't coerce anybody to be anything. We believe there's no such thing as coercion in spirituality. If you want to eat ham on Yom Kippur, that's your business. It doesn't make you less of a person or a better person. "He can do without my blessings, without my Shabbat, everything. The one thing He can't do without is my interaction with you, with other people. I think it's more important what goes out of our mouth than what goes into it." WHETHER IT was that kind of thinking or something else that provided the attraction, the Kabbalah Center in its 51 locations around the world became a haven over the last decade for secular Jews, gentiles and wayward celebrities who had been unable to find spiritual fulfillment in other spheres. Berg accepts them all, and the formidable fees for classes and courses mean that usually the students who attend are serious about it. "People are taking hold of this because, especially with what's going on in the world today, they are thirsty - thirsty for truth, and not looking for a quick fix," said Berg. "There are those that are looking for a quick fix, and they end up leaving right away. Kabbalah's not easy. We ask you to do things for it. Sometimes people like the idea of just learning and not having to use it. That doesn't work with us. "Some people think Madonna is the epitome of pop Kabbalah, but look, she's been a serious student now for 12, 13 years. She has a ravenous appetite for knowledge. But today, partially thanks to her studies, she's humbler than I've ever seen her before, and sincerely grateful for the appreciation of the people around her." Berg emphatically stated that the Kabbalah Center goes out of its way not to exploit the celebrity potential of its student body. "We would never go, 'Hey, come to us because so-and-so is studying here.' That's ridiculous, and it wouldn't be fair to the celebrity. At the end of it all, they're just people and they're searching like anyone else." THAT'S ALSO the reason that the Kabbalah Center in Tel Aviv has gained a stronghold within secular society, with more than 800 students taking classes. Berg admitted, though, that there are differences in attracting an Israeli audience to their pluralistic, nontraditional form of Kabbalah. "There are more religious people here. And even those that are secular have a connection. And that's fine. If people are satisfied with their lifestyle and their plane, then that's fine, maybe they don't need more than that," she said. Regardless of any hiccups, the country plays a major role in Kabbalah Center studies around the world. It urges all students to visit within their first two years of study, and two years ago, more than 2,000 students including Madonna attended a Rosh Hashana conference at the Tel Aviv center. "We didn't do it this year because we were afraid of the economics involved and worried that people might have felt they have to come and didn't have the money, and we didn't want to push them. Hopefully next year will be better," said Berg. When Madonna "expressed herself" to the crowd at her two shows that Israel is the energy center of the world, she was taking her cue straight from the Kabbalah handbook. "The energy of Israel is very important, important because it's the energy center of the world," reiterated Berg. "We're now looking for land to make our own yishuv, a place that teachers can stay and people can come and learn for a week, a year, a day. But right now, it's just in the early stages." With big plans for the future, Berg is relying more on the help of her sons, Michael and Yehuda, who are both integrally involved in the center and have written books on Kabbalah. Their input spiked when the Rav suffered a stroke five years ago which has left permanent damage. "He's a walking miracle because he walks and talks, even though the stroke affected both of his lobes," said Berg. "But he's lost a lot of veils - he says what he wants to say and he's lost a lot of his memory. But when he walks into a room, people who don't know him think he's fine." As the aroma of medium-rare entrecote wafted into the living room, Berg paused and thought about the contribution that she and the Rav were going to leave the world with. "I hope our legacy will be that the teachings and word of the spiritual essence of Judaism - the Kabbalah - will be taught to every single person," she finally said. "My legacy will be that we started that path. We created the movement that will allow people from any walk of life to learn. And I think that's great."