The Zohar, Chapter “VaYikra (The Lord Called),” Item 108: Hence, since the sins of the lower ones blemish above, they offer a sacrifice. That offering is as it is written, “And for your transgressions was your mother put away,” where the sin causes separation between ZA and Malchut for his flaw, since Malchut was sent away due to the sin. And the offering that they sacrifice brings the upper world, ZA, closer to the lower world, Malchut, and everything becomes one.
Man never willingly commits a sin. If he knows for certain that he would be committing a sin, he would not be able to do so. He sins only if he doesn’t know or doesn’t consider the act a sin. It is impossible to sin before the Creator, but can only do so if He is concealed, which no longer makes it a sin.
All the sins mentioned by the science of Kabbalah have taken place from above downward by the Upper Force. When ascending from below upward, we never sin. We merely reveal the sins that exist in us from Him in the first place.
The Creator created the evil inclination; no greater or other evil could have been done. He turned Himself into a polar opposites, placed this oppositeness into us, and is gradually revealing it to us. All the evil that we are presently revealing within is but the smallest measure of oppositeness to the Creator that exists within us.
As we ascend the spiritual ladder to the World of Infinity, we will continue to reveal evil within in increasingly greater degrees of oppositeness to Him, until the Creator becomes revealed within us on the level of Infinity as a polar opposite of Himself. The evil within us will be infinitely great, but at the same time we will have the strength to oppose it.
From the 1st part of the Daily Kabbalah Lesson 5/20/10, The Zohar