Like our Sages say, (Megilla 31a) “In the place where (you think you) find His greatness, there you (really just) find His humility.”
Even though “His greatness (that we perceive in the creation) cannot be understood,” (Tehillim 145:3), nonetheless, He is way beyond the “greatness” that we are able to perceive, so that His “greatness” is considered like “humility” and “lowering Himself.”
When a truly great sage plays checkers with children and shows them how well he knows the game, much better than they possibly could, this is just his humility that he is lowering himself to their level to even be involved with them. In truth, the fact that he is even talking about checkers is just his humility. He would rather focus on loftier matters. So too, the “greatness” of Hashem that can be perceived within creation (despite the fact that it is completely impossible for human understanding to grasp even the slightest details of how Hashem created the world), is really just Hashem’s humility, since He must lower Himself have any involvement with the world.
When a person will reflect deeply into understanding and contemplating this and similar concepts, then automatically “all the workers of evil will disperse,” (Tehillim 92:10), meaning that the bad in his animal soul will dissipate.
Since the bad and the “opposite side from holiness” has no life of its own at all, it only receives its life from the “outermost aspect” of holiness, through the possibility of a Jew transgressing against one of the 365 Negative Mitzvos (that command us what not to do).
The “outermost aspect” of holiness in this context: Hashem wants us to have free choice to choose to serve Him. Therefore, He “allows” unholiness to exist so that we can choose not to follow unholiness. Unholiness does not exist for itself, but only to enhance the side of holiness, so that holiness can overcome and negate unholiness. Therefore, the life-force of unholiness is described as being from the “outward aspect,” since it is only an “external” consideration that exists for some other purpose. It does not have any essential value or merit.
They are, therefore, nullified to a revelation of and appreciation of holiness, just as physical darkness is dispelled before physical light.
Since unholiness receives its life from the possibility of choosing against holiness by transgressing against the Mitzvos, when a Jew comes to love Hashem and dedicates himself to keep the Mitzvos and not commit any sins, this removes life from the unholiness of his own animal soul and from the unholiness of the world in general.
