The Midrash states that before the creation, G d foresaw the deeds of the righteous, and created the world on their account.
However, the world that G d desired to create on their account was overflowing with love for them. As such, it was unable
to exist in the Divine Effulgence.
G-d therefore looked at the deeds of the wicked, which resulted in a withholding of His light. But it was precisely this withholding
that allows the world to exist. There is a constant pendular movement, between the desire to create and the desire to restrain.
This is known as "below and not below."
According to the teachings of the Arizal, the first stage in creation was the tzimzum; the contraction of G-d's light to make
room for the existence of a finite universe.
Gevurah means "strength" or "power," and refers to the forces of contraction and restraint that G d used in creating the world.-
As the Mishnah says in Pirkei Avos 4:1: "Who is strong? One who subdues his own nature."-
Implied in both this teaching and the previous one is that deeds of the wicked also contain a point of goodness, since they
provide the context in which G d could create the world. This reflects the Baal Shem Tov's teaching that there is a spark
of holiness in all things, and that light shines greater when it comes out of darkness.
(source researched on-line, credit and link to be included)