Pop superstar Madonna is studying Islam's holy book, the Koran. The singer, a devout follower of the Judaism offshoot Kabbalah, is currently dating Muslim Brahim Zaibat and has taken an interest in the religion by reading the holy book. She tells Harper's Bazaar magazine, "I am building schools for girls in Islamic countries and studying the Koran. I think it is important to study all the holy books. "As my friend Yaman always tells me, a good Muslim is a good Jew, and a good Jew is a good Christian, and so forth. I couldn't agree more. To some people this is a very daring thought." The Material Girl hitmaker was raised as a Roman Catholic but has been a devout follower of Kabbalah for the last 17 years.