The essence of life in the world, as formulated in Jewish writings, is exemplified by the terrible progress of the divine fire (Ezekiel I) to and fro, up and back-the constant rhythm of the breath and the heart’s blood.
This principle of fluctuation seems even to be at the root of man’s relation to Heaven and earth, evinced as the urge to extricate oneself from the bonds of matter and rise toward the Divine, and the equally urgent need to return to the world, with its problems, its substantiality, its life of sadness.
To remain in anyone condition of being, above or below, represents a cessation of effort, a dying, and therefore an evil.
–Rabbi Adin Steinsaltz