"A multitude of worlds are attached to each and every Sefirah, filled with its potencies, that break out of the divine realm and realize the particular essence of that Sefirah in descending degrees...
..the fire of wrath burning in God...is a holy quality within the divine totality. So long as it operates within the union of all the Sefiroth it is not evil, although it is the source of evil (as Boehme put it, the Urqual, the primal source of evil.)
The fire of divine severity melts and refines the power of judgment, known as the sacred gold; however, the dross is externalized becoming the "shells" (kelippoth) in which the holy is either nonexistent, or present only as a spark, concealed and glowing within the dross. In the language of the Zohar, this is the Sitra Ahra, the "Other Side," which is the opposite of the holy and schemes to seize it and draw it over to its own side. The Other Side is the fire of divine severity, externalized and made independent, where it becomes an entire hierarchial system, a counterworld ruled by Satan.
Once removed from its joint root with the Tree of Life, the Tree of Knowledge itself becomes a "Tree of Death".
..a spark of the divine light shines even in evil...One theory states that independent of human conduct, such a spark from the primoridal light fell into the so-called "Emanation of the Left Hand"--the system of the Stra Ahra and is still glowing within the slag of evil. It could be argued that this spark was drawn there during the eruption of that emanation, and is now held captive, so to speak, awaiting its redemption to be returned home. This was the theory of Lurianic Kabbalah: upon the "Breaking of the Vessels" that great drama in the Sefirotic world that constituted the turning point in the theosophic proccess. ...Along with the shards of these shattered vessels, from which the "shells" or kelippoth were thereafter formed, a few sparks of the inner light from the world of Adam Kadmon likewise broke away and descended. It is these sparks (nitsotsoth) that now shine even in those spheres over which evil gains control. Their activity is strangely ambivalent: on the one hand, these sparks animate evil, guaranteeing its existence and its power of action; on the other, they are like captives, awaiting their own redemption from evil. The Kabbalists disagreed as to whether the removal of these sparks would destroy the sphere of evil, by depriving it of its vitality, or whether it would redeem evil as well, transforming it and returning it to the reconstituted harmony of things.
In Kabbalistic theory, this proximity and interlacing of good and evil finds its classical expression in the notion of a sphere in which these two emanations are blended, and which has special significance as the source of souls--namely, kelippath nogah, the "brilliant shell." This conception originated in a mystical reading of Ezekiel's vision of the Merkavah, in which the prophet saw "a stormy wind come out of the north, a great cloud, with a fire flashing up, so that a brightness was round about it: and out of the midst therof as the color of electrum, out of the midst of the fire" (1:4). This world of kelippath nogah is actually a Luciferian world, belonging to the domain of shells and hence of evil, but is penetrated by a brilliance from the world of the Sefiroth that shines within it, so that the realms of good and evil appear uncannily blended. The souls that originate in this realm bear the stigma of this unresolved essential conflict. According to Lurianic Kabbalah, man's natural soul, with all its powers, derives from this source of kelippath nogah, and hence enjoys the possibility of choice between good and evil that is the lot of every human being, even without the influence of the divine soul within him stemming from the light of the Sefiroth. The doctrine of kelippath nogah is the classical form in which the Zoharic doctrine, according to which the world of evil is independent of man, but rooted in the dialectics of emanation itself, became most widely known and influential.