I'll try to make this as simple as I can.
Kabbalah is a multi-volume ancient Rabbinic text, with unbelievable depth, extremely difficult to understand, recommended not to be studied until the age of 40, requires years of intense learning, and a background of many years of serious Torah study to even begin to understand it.
To assign ANY credibility to Madonna or her other Hollywood cohorts having the slightest idea of what Kabbalah is supposed to be is a complete travesty.
And BTW, who is Rabbi Berg?
Essentially a huckster in the long tradition of American Charlatanism that includes Billy Sol Hargis, Jim Jones, Father Devine, etc. Usually, they're Christian, but Rabbi Berg has proven that that is not always the case.
"Feivel Gruberger", an insurance agent, married a niece of authentic kabbalist Rabbi Yehudah Brandwein and sold his books. He then ditched that wife and many children for his current wife Karen, but still claimed association with the teachings of his former father-in-law, vehemently denied by everyone connected with Brandwein. "Berg" has no respect, either in the academic or religious world.