In Pachad Yitzchak, Yom Kippur 1, Horav Yitzchak Hutner, zl, cites Rabbeinu Yonah (Shaar 2:14) who writes: “It is a positive mitzvah of the Torah for a person to awaken his spirit to return/perform teshuvah on Yom Kippur.” He quotes the above pasuk which intimates that it is a specific mitzvah to perform teshuvah on Yom Kippur (exclusive of the mitzvah to repent from one’s sins at all times). The Rosh Yeshivah wonders wherein lies the difference between teshuvah all year and teshuvah on Yom Kippur. He explains that the mitzvah to repent all year/all of the time, whenever one sins, is derived from the pasuk (Devarim 30:2), V’shavta ad Hashem Elokecha, “And you will return unto Hashem, your G-d,” while the teshuvah of Yom Kippur is derived from the above pasuk, lifnei Hashem titharu, “Before Hashem shall you be cleansed/purified.” Apparently, a difference exists between “standard” teshuvah and taharah.
Sforno explains that complete purity and forgiveness are possible only before Hashem, for only Hashem knows the sincerity of an individual’s teshuvah. Yom Kippur is when the one who repents receives his certificate of taharah, purification. Horav Gedaliah Schorr, zl, derives from the pasuk that the removal of sin is comprised of two distinct aspects: atonement and cleansing. Committing a sin leaves a stain on one’s soul/spiritual persona that he must cleanse. One who sins earns a punishment for disobedience. In addition, he is now more likely to sin again, since his spiritual resistance has weakened. Atonement removes the punishment liability; yet, the individual has not yet expunged the noxious effect of the sin on the soul. Enter teshuvah on Yom Kippur, a day of intense prayer and physical affliction, the time at which Hashem will vacate the sin of one whose repentance is the product of a sincere heart, and purify his soul.
Perhaps, we may expand on the distinction between teshuvah and taharah. Teshuvah is the process in which the sinner returns to Hashem by rectifying his actions, thoughts and emotions. It is a personal journey of rectification, regret, and a commitment to better oneself. Teshuvah also includes working to close the gap in his relationship with Hashem which he breached through his errant behavior. Thus, teshuvah is about our relationship with Hashem. Our actions have distanced us from Him; Teshuvah helps us to return.
Taharah is about cleansing one’s soul from the effects of sin. While teshuvah repairs his relationship with Hashem, taharah is the spiritual purification that allows one to regain his inner sanctity. Hashem welcomes us home once we repent, but why would one want to “sit at the table with soiled garments”? Taharah effects the cleansing; it completes the job. Yom Kippur is the day of atonement/teshuvah, as well as the day of taharah, when we restore our spiritual purity.