Heinrich Cornelius Agrippa's von Nettesheim Magische Werke
Kabbalah developed within Judaism, and kabbalists often use classical sources held by Judaists to explain the inner, real meaning of the Bible and Rabbinic sources. Regardless of Kabbalah's definition, it is an integral part of Judaism, Christian, New Age, and Occultist western esoteric religious systems. For centuries, Kaballah was a concealed teaching. The study of Kabbalah was available only to Jewish scholarly comprising of married Jewish men over the age of forty, and forbidden to all others. This tradition of hidden knowledge existed until 1960s when it started to be popularized by some of the teachers.