On Purim we are required to elevate our understanding to the point that we perceive no essential distinction between Mordechai and Haman. For the ultimate goal in the creation of Haman is that he become a force for good - like Mordechai.
The threat posed by Haman endangered the very existence of the Jewish people. In response, they demonstrated self-sacrifice and dedication to Torah which transcended the limits of reason.
Their commitment transformed the entire nature of the situation. Thus, instead of destroying our people, Haman’s plot enriched us with a festival and a day of rejoicing.
Within the limitations of this world, understanding represents the highest of our faculties. G‑d’s essence however, is not bound by the limits of our faculties: it transcends all definition and restriction.
“The ultimate in knowledge is 'not to know'." Reason, is by nature limited, and prevents the expression of our unlimited potential. The divine service of — self-transcendence — is the goal of our drinking on Purim.
The state which transcends the limits of reason is related to the concept of transforming evil to good.
From an intellectual perspective, good and evil have clearly defined boundaries. The infinity of G‑d’s essence (and the potential of our souls) is not bounded by these limitations. At that level, “darkness is like light.”
Regardless of a person’s state, he is always able to turn to G‑d in repentance. And his sins are then transformed into good.
Purim means “lots”, and casting lots symbolizes a step above the realm of the rational.
During the time of the Purim miracle, the Jews rose to a level of commitment to the Torah that transcended the realm of intellect. And that is what brought about the transformation of evil into good. Instead of the annihilation of the Jewish people, we merited great deliverance.
May the darkness of this exile give way to the light of Redemption!