The system that reaches us under Luria's name begins with a question older masters had left alone: if God is everywhere, where can a world be? The answer taught at Safed is tzimtzum, contraction. The Infinite withdrew itself from a point, so to speak, to clear a space in which creation could stand. Into that cleared space poured a ray of divine light, caught in vessels prepared to hold it; and the vessels failed. Shevirat ha-kelim, the shattering of the vessels, scattered sparks of light into the depths, where they lie captive in husks, the kelipot, which are the stuff of evil and of matter. Everything that follows, in this reading, is rescue.
The human task is tikkun, repair: every commandment performed with intention, every prayer, every ethical act frees sparks and restores the broken configuration of the divine face. History itself is the long labour of gathering, exile is at once the condition of the sparks and of Israel, and the soul returns in gilgul, transmigration, until its share of the work is done. The power of the scheme is that it makes cosmology, ethics and messianism one mechanism: the end arrives not when heaven decides but when the last spark is raised. Gershom Scholem read it as Jewish history after the Spanish expulsion projected onto the cosmos, catastrophe built into creation itself and hope built into daily practice, which is much of why it conquered the Jewish world within a century.