Tum'a is an obstacle to kedusha. The fact that the dwelling of God is in the midst of the Jews makes the presence of tum'a a dangerous situation. This gives us the basic ingredient in understanding what is tum'a of a person. Tum'a is a state which interferes and prevents the relationship of a man with the sacred, with kedusha. At the strongest level, it prevents the integration of the tamei with the sacred community of Israel, on a less severe level it obstructs his entrance into the realm of God's service, on the weakest level, it interferes with his coming into the presence of God.
Death is the opposite of relationship to the source of life, growth, and kedusha.
Today, we shall try to see what can be derived from metzora, rather than met. If atonement is part of the process of the return of the metzora, it is clear that there is something for which he must atone. Being a metzora is a state that requires atonement. That is why there is a confession of the kohen gadol over the goat. The basic meaning of kappara is not forgiveness of sin but redemption from a state that needs redemption.