The Midrash (Koheles Rabba 7) tells the following mashal:
A band of thieves was in jail. One of them dug a hole so that he and all his friends could escape. Only one of them remained behind. When the person in charge saw the one who remained behind, he hit him. "The tunnel was dug, why didn't you escape?"
The Midrash says that Hakadosh Baruch Hu says the same to the sinners. "You had the opportunity to do teshuvah; why didn't you utilize it?" Rabbeinu Yonah (Shaarei Teshuvah 1:2) writes, "Know, when a sinner pushes off doing teshuvah, his punishment increases daily. He knows Hashem is angry with him, and he has a place to escape –to teshuvah – yet he remains with his sins."
Rabbeinu Yonah (beginning of Shaarei Teshuvah 1:1) writes, "From the favors Hashem yisbarach performed with His creations is that he prepared a path for them to leave their bad deeds, to escape from their sins, to save their souls from Gehinom, and to remove Hashem's wrath from them. He taught them and commanded them to do teshuvah when they sin to Him, for He knows their yetzer hara. As it states (Tehillim 25:8) בדרך חטאים יורה כן על 'ה וישר טוב, 'Hashem is good and upright; therefore, He leads sinners on the road.' Even if they sinned a lot and they rebelled, Hashem didn't close the doors of teshuvah from them. As it states (Yeshayah 31:6) סרה העמיקו לאשר שובו, 'Return to Him, against Whom you have deeply turned away.' And it states (Yirmiyahu 3:14) בנים שובו משובותיכם ארפא שובבים, "Return rebellious children..."
How does teshuvah remove aveiros? There are several explanations and paths: Chazal say that when one does teshuvah, he becomes like a newborn child (שנולד תינוק). The Bas Ayin explains that this is the root of his forgiveness. He isn't the same person who performed the aveirah.
Rebbe Yissachar Dov of Belz zt'l says that this is the reason we say שהחיינו on Yom Kippur night. We are saying it on our renewed selves, due to our teshuvah. He explains that if the שהחיינו were solely for the yom tov of Yom Kippur, there would be reason not to say this brachah, due to the fear of judgment. But on Yom Kippur, we can certainly say שהחיינו, because each person became new, due to his teshuvah.
The following is another explanation of how teshuvah works. When one does teshuvah, his aveiros turn around and become mitzvos, as the Gemara (Yoma 86.) states, גדולה כזכיות לו נעשות שזדונות תשובה, "Teshuvah is great because the aveiros become merits." There are various explanations on how this works; however, it remains a fact, when one does teshuvah with love of Hashem, his aveiros become merits.
Rebbe Yitzchak Meir of Zinkov zt'l met someone worried about his aveiros. Reb Yitzchak Meir told him the following idea that he heard from his father, the Apter Rav zt'l:
The Navi (Yirmiyahu 50:20) discusses the era of Mashiach. ישראל עוון את יבוקש ,'ה נאום ההיא ובעת אשאיר לאשר אסלח כי תמצאנה ולא יהודה חטאת ואת ואיננו, "In at that time, says Hashem, the sins of Yisrael will be sought, but they won't be there. And [they will search for] the sins of Yehudah, but they will not find, for I will forgive those I leave over." It seems from this pasuk that people will be searching for sins. Why?
The Apter Rav zt'l explained that every aveirah is a zero. When one repents with love, the teshuvah is a number placed before all the zeros, turning it into a vast, large number. In the future, people will look for sins because the aveiros will increase their merits and virtues."
Stories:
20. Reb Baruch Ber zt’l (the Birchas Shmuel) excelled in the mitzvah of honoring his parents, and when his father was sick, Reb Boruch Ber stayed with him almost every night. One night, he couldn’t be with his father, so he appointed someone to take care of his father in his stead. Unfortunately, that night, his father was niftar. Reb Baruch Ber was devastated. He thought repeatedly, "If I were there that night, perhaps he wouldn't have died. Why wasn't I more devoted to my father?" The shivah passed, but Reb Baruch Ber couldn’t return to yeshivah to give his shiurim. His spirits were down. He was afflicted by guilt. He traveled to Radin to seek encouragement from the Chofetz Chaim zt'l. The Chofetz Chaim told him, "When one does teshuvah, he becomes a brand-new person. He isn't the same person who did the aveirah. This is how teshuvah atones. He is no longer the person who committed the aveirah." Reb Baruch Ber came out of the Chofetz Chaim's house singing and dancing. He shouted, "I'm a new Baruch Ber! I'm a new person!"
21. The Bardichover Rav zt'l once told a great sinner, "I am jealous of you because when you do teshuvah, you will have so many mitzvos." The man replied, "Just wait another year, and you will have even more reason to be jealous." The Tiferes Shlomo (Radomsk) zt'l visited the renowned baal teshuvah, Reb Chaim Dovid Doctor zt’l, when Reb Chaim Dovid was on his deathbed. Reb Chaim Dovid moaned, and the Tiferes Shlomo assumed he was crying over the sins of his youth. The Tiferes Shlomo told him, יפלו הראשונים הימים, "The early days will fall away." As if to tell him, "Don't worry about the past. You did teshuvah, and you won't be punished. Those early days aren't part of your life." Reb Chaim Dovid Doctor replied, "Chas veshalom! I'm not mevater on a single day!" Reb Chaim Dovid Doctor didn't want to lose one day of his life, even the days when he was irreligious. Because he did teshuvah through love of Hashem, his previous days were now included among his merits.
