There are various ways to view an occurrence, especially if it takes place following sinful behavior. The common perspective is that if the event follows a sin, especially if this event is accompanied with physical and emotional pain, it is a punishment for the preceding transgression. Someone with a penetrating cognitive gaze might see beyond what appears to be a punishment and define it as restorative and purifying. This is how we should look at the tumah of tzaraas.
The Torah decreed that the tumah of tzaraas (spiritual leprosy,) as well as its purification, be declared by the Kohen. One of the primary causes of tzaraas is speaking lashon hora, evil/slandering speech. The Kohanim, as descendants of Aharon HaKohen, inherited their saintly forebear’s character trait of oheiv shalom v’rodeif shalom, loving peace and pursuing peace. They were granted the merit to serve as healers, to heal the metzora from his impurity. A man slandered his fellows, causing a rift in a relationship, in a community. The Kohanim were there to purify him, a healing that is facilitated through an individual whose love for the community in general, and for each individual Jew in particular, knew no bounds. All this was understood. Cure and purification was brought about by the person who cares the most. Why then is this same “loving” Kohen the one who originally declared the tumah, rendering the metzora impure?
The Sfas Emes explains that tzaraas itself was not a disease; rather, it was a cure. The metzora stands for motzi ra, brings out/publicizes evil. It also means, remove the evil. In the latter interpretation, the affliction of the skin which is concealed within the skin of the person emerges and is revealed, allowing for him to be cured. We all have to deal with our personal issues, evil demons (whatever term is most comfortable for one to accept). The bottom line is: The ability to see and come to terms with one’s own lowliness/evil is the first step toward teshuvah, repentance and reconciliation. The Kohen’s judgment did not cause the tumah; rather, it drew the internal flaw/blemish to the exterior, to a place where it could be treated effectively, resulting in a cure.