A young student, eager to master all the secrets of Kabbalah, approaches his revered teacher and master. The student is lugging along a box containing 22 sacred volumes of Kabbalistic books. He lays the heavy box down with a thud in front of his master and pleads with him to teach him all of its sublime secrets and magnificent mysteries in the short time that it takes to remain balanced on one leg.
This eminent Kabbalist is one of the greatest spiritual giants to ever walk this earth. Upon hearing his eager student's request, he considers the question very carefully. His eyes then sparkle with infinite wisdom ... and he says:
Love thy neighbor as thyself.
All the rest is mere commentary.
- from The Power of Kabbalah, Yehuda Berg