The penitent does more than return to his proper place.
He performs an act of amendment of cosmic significance.
He restores the sparks of holiness which had been captured by the powers of evil.
The sparks that he had dragged down and attached to himself are now raised up with him, and a host of forces of evil return and are transformed to forces of good.
This is the significance of the statement in the Talmud that in the place where a completely repentant person stands, even the most saintly cannot enter;.
Because the penitent has at his disposal not only the forces of good in his soul and in the world, but also those of evil, which he transforms into essences of holiness.
–Rabbi Adin Steinsaltz