A History of the Jewish Experience, by Leo Trepp (2001)
According to the Ari (Isaac Luria, 1534-1572), in order to make room for the world that God was about to create, God retreated and abandoned a part of the divine omnipresence. This act of withdrawal, called tzimtzum, preceded creation; in a sense, God went into exile in order to make room for creation. Then God created the world out of the void, reentering it through creation and revelation. At creation, the divine light flowed into the tzimtzum. The first creation is Adam Kadmon, primordial man, wholly spiritual, first and highest form of the manifestation of En Sof. Divine light from Adam Kadmon flowed into the sefirot. Since finite beings were to be created in accordance with the sefirot, the sefirot needed bowls, vessels, to hold the light. The first three sefirot could hold the light, but when it broke upon the seven lower sefirot, they could not hold the light and the vessels broke. The broken shells, kelipot, to which some of the holy sparks adhered, sank into the uttermost regions of primordial space, the abyss, where the spirit of evil dwells. Through the breaking of the vessels the union of the universe within itself and with God was torn apart, and the universe and the human world were torn in catastrophic conflict; the unity of God in the world had been broken. The Shekhinah fell when the vessels broke and, as the sefirah, is in exile.
The powers of evil must be transformed into powers of love, the world must be mended, and the manifestation of God be restored to unity. This is the work of tikkun, restoration. With the beginning of tikkun, the Shekhinah acquired new strength. Placed in the hands of humanity, tikkun is advanced in the process of history, and the Jew has a special function in bringing it about; the Jew's kavannah must be directed toward this goal. The divine sparks are scattered throughout the entire world, and Israel, like the Shekhinah, is called to go into exile to the very ends of the world to gather them.
Tikkun, given a modern meaning as the call to promote unity and justice throughout the world, is perceived by modern Jews as a paramount task, challenging both Jews and non-Jews alike. A Jewish periodical bears this name.
- P. 480-481