The Kabbalah Unveiled: (A Timeless Classic) by S. L. MacGregor Mathers
"I. The first questions which the non-qabalistical reader will probably ask are: What is the Qabalah? Who was its author? What are its sub-divisions? What are its general teachings? And why is a translation of it required at the present time?
2. I will answer the last question first. At the present time a powerful wave of occult thought is spreading through society; thinking men are beginning to awake to the fact that "there are more things in heaven and earth than are dreamed of in their philosophy;" and, last but not least, it is now felt that the Bible, which has been probably more misconstrued than any other book ever written, contains numberless obscure and mysterious passages which are utterly unintelligible without some key wherewith to unlock their meaning. THAT KEY IS GIVEN IN THE QABALAH."
S. L. MacGregor Mathers