The tikun, or repentance, of the baal tshuva, the one who returns to the fold, does not necessarily deal with the depths of evil.
Whereas the tikun of the one who stands up to a trial experience does get to the depths.
It has to reach the roots of the evil that is being confronted in order to contend with it.
It's not a matter of something that was done in the past; one must wrestle with a present evil whose grip must be overcome.
By so gaining a certain supremacy, one approaches sanctity.
The power of the evil that was overcome becomes a seat of goodness that can be a step towards holiness.
The one being tested does not struggle only against the consequences of evil, that which was done in the past.
He struggles against evil as it faces him, and endeavors to extirpate its power.
He has to uproot, to eliminate from himself, the very essence of evil, and thereby, he comes closer to sanctity.
There is a transmutation of evil here into an instrument for the release of a spark of holiness, which transmuted spark is somehow higher and more complete than other sparks.
The work of the trial experience thus raises the holy sparks very high, more so even than does the action of the positive mitzvah.
It can be said to occur on an exalted level of the spiritual life, in spite of accompanying difficulties; and its tikun is correspondingly outstanding and unique.
Indeed, the greater the trial and the more intense the struggle, the more profoundly does it change and rectify the essence of evil.
Rabbi Adin Steinsaltz
From The Candle of God, "The Trial of Life," p. 311, by Rabbi Adin Steinsaltz