“True teshuvah is when a person craves to return to God with the same intensity, with the same turmoil, as the craving he experienced at the time of his sin.
The sin does not then become a mitzvah, but the teshuvah redirects it to function as a mitzvah does, as an impetus of bringing a person closer to God”
From Opening the Tanya, p. 195, by Rabbi Adin Steinsaltz