The esoteric teaching, the Kabbalah, is the inner part of the Torah that explains the metaphysical significance of every single movement and thought, and ultimately of the whole essence of the world.
The man who attains genuine knowledge of the wisdom of the Kabbalah can, in certain respects, use the keys provided by this wisdom to reach a deeper and more complete closeness to God, and is able to change and "repair" the world in which he lives.
–Rabbi Adin Steinsaltz
In "The Ari," in The Strife of the Spirit by Rabbi Adin Steinsaltz