According to the other Sages, even though Yom Kippur atones for the Jewish people as a whole, it does not exempt individuals from the punishment they deserve. Even if it is possible that a delay in the punishment would allow a person time to repent and correct his deeds, if he fails to repent on Yom Kippur, he will feel the full force of the law. However, even these Sages agree that a person does not have to achieve perfect repentance for Yom Kippur to atone. The fact that on Yom Kippur he refrained from melakha, fasted, prayed, and showed his inner wish to be good and not sin, is enough to protect him from the punishment due to him according to the letter of the law (3:5 above, based on Shlah, Masekhet Rosh Ha-shana, Torah Or §17).
The Rishonim rule that the halakha follows the Sages, and Yom Kippur atones only for those who repent. Nevertheless, if we truly internalize R. Yehuda Ha-Nasi’s words concerning the inviolable connection between God and the soul of each and every Jew, Yom Kippur will inspire us to repent out of love.
Everyone agrees on the following. If someone was obligated to offer an asham talui (as he was uncertain about whether he had committed a sin requiring a sin offering), Yom Kippur wiped out this obligation. Even if he did not repent, and even if he desecrated Yom Kippur by working and eating then, simply undergoing the day exempted him from bringing the offering (Keritot 25b; MT, Laws of Sin and Guilt Offerings 3:9).