Zohar 2:184a

Jewish Mysticism
The words of Torah reside only there, for there is no light except that which emerges out of darkness. When that [Other] Side is subdued the Holy One, blessed be He, ascends and is glorified. And there is no divine worship except amidst darkness, and no good except within evil. When a person enters an evil way and forsakes it, then the Holy One, blessed be He, ascends in His glory. Thus the perfection of all is good and evil together, and afterwards to ascend to the good. . . . This is complete worship.

Translated by Elliot Wolfson in “Light Through Darkness- The Ideal of Human Perfection in the Zohar,” Harvard Theological Review 81 (1988)- 73-95.