Teshuva
The Rectification of Teshuva:
Rav Sinai of Zemigrad zy"a (Sefer Chemda Genuza) relates the following story:
There was a Sanzer chasid named R' Shimshon who lived in the city of Kishinov. He once met a friend of his who looked very sad. He asked him what was wrong, and his friend told him that, due to a specific occurrence, he had violated the sanctity of Shabbos. He told Rav Hillel of Kolomaya zy"a what he had done, and Rebbe gave him a very difficult regimen of teshuva that he must do. These rigorous tikkunim had caused him to become depressed.
Rav Shimshon advised his friend to come with him to Sanz and present his problem to the Divrei Chaim zy"a, and the man agreed to go.
When the man told Rav Chaim what he had done, he didn't give him any hard tikkunim. He only told him to do one small, easy thing.
He was full of joy as he left the room. R' Shimshon then went in and told the Divrei Chaim about the hard forms of teshuva Rav Hillel had ordered his friend to do. Rav Chaim told him, "Let me explain this to you with a moshol.
"There once was a wealthy man who owned a big grocery store that sold food at a low price. He once saw his wife shopping in his store. She went to pay for a chicken and, when she got to the cashier, she asked her to give her a five-dollar discount. He wondered why she was making a big deal out of such a small amount of money. After all, he thought, he always gave in on small amounts when he sold products in his store. He kept wondering until he realized that she was correct. If a baalas habayis wouldn't care about even small amounts of money, she very likely would not keep any budget and would run through all the money in the house. He, on the other hand, as the owner of a large store, couldn't make a big fuss over every few dollars. He couldn't demand five dollars more from every customer because, if he did so, he soon wouldn't have any customers at all."
The Sanzer Rov concluded, "That's how it is here as well. I am 'running a big store', so I have to give tikkunim away 'for cheap'. Rav Hillel is running a 'small household', so he has to make careful calculations to keep the house in order."
One Who Sins to Still His Desires Can Still do Teshuva:
Nothing can stand in the way of teshuva. Even if one fully knows that something he is doing is wrong, and he only does it to still his desires, he can repent.
The Gemara says (Yoma 85B) that if a person says, “I will sin and then I will repent", he is not given the opportunity (ain maspikin) to do teshuva. The Sanzer Rov zt'l explains this Gemara in a positive way. He translates it as saying: "If one says that he will sin, but even while he is sinning, he says that he will do teshuva and he is only doing it to still his desires, then “ain maspikin", there is no doubt (safek) that he will have the opportunity to do teshuva.
Hashem Waits for Us More than a Father Waits for His Son:
One of the respected, elderly residents of Yerushalaim was named R' Nochum Yazar zt"l. In his younger years, he lived in Russia, where he taught Torah for many years. Sadly, one of his sons got caught up in communist ideology and abandoned Yiddishkeit. This was a tremendous source of pain for R' Nochum.
One day, R' Nochum was teaching his students the Rambam in Hilchos Teshuva (7:6) that says: “Teshuva is great as it brings a person close to the Shechinah... Teshuva draws close those who are far. Yesterday, this person was hated by Hashem. He was disgusting, far-off, and abominable. Today, he is beloved, precious, close, and cherished."
The students asked how one moment of teshuva could change things so greatly, to the extent that Hashem considers it as if the person never sinned and He is no longer angry with him at all. Rav Nochum answered, "You should know that if my son would knock on my door and say that he misses me and wants to come back, the love I would feel for him would be indescribable. Although he caused me a lot of pain in the past, at that moment it would all be forgotten. So why do you think that Hashem can't do the same thing?"
He then quoted the Tana D'Bei Eliyahu (Rabbah, Perek 31) that says: "I testify that Hashem is sitting and eagerly waiting for Yisroel more than a father waits for his son or a woman waits for her husband."
He said, "Imagine the scene. It is late at night, and a man has yet to return home. It is midnight or 1 am, and he is nowhere to be seen. The entire time, his wife is sitting by the window to see if he is coming. Tana D'bei Eliyahu is saying that Hashem waits for us even more than that. He is sitting by the window of Heaven, looking to see if we are returning to Him. He is always waiting to greet us as soon as we do teshuva."
Commitment for the Future:
Sefer Darchei Hayashar V'Hatov (Chelek Bais, page 23) relates that Rav Tzvi Hirsch of Liska zy"a once spent Rosh Hashanah in the court of Rav Tzvi Hirsch of Rimanov zy"a. He related that before Kiddush, Rav Tzvi Hirsch said, "People think teshuva is very difficult. But the truth is that teshuva just means resolving not to do what we have done until now."
The Liska Rebbe said that these holy words made a strong impression on him, and he felt as if a massive weight was lifted from him.
Teshuva in a Short Time:
The Mishnah states (Avos 4:10): “One hour of teshuva and good deeds in this world is better than all of life in Olam Haba." Chazal (Avodah Zara 10B) say similarly that one can acquire an entire world in "one hour."
Rav Aharon of Zelichov zy"a (Sefer Ohr Haganuz L'Tzadikim, Parshas Netzavim) writes that "one hour" doesn't literally mean an hour of 60 minutes, as teshuva is not bound by any specific amount of time. Rather, it simply means a very short amount of time, as one can even do teshuva in a moment. This is as the Gemara says (Kiddushin 49B) that if one marries a woman on condition that he is a tzadik, the marriage is valid, even if the man is a rasha, because we suspect that he may have had a momentary thought of teshuva.
He concludes by saying that when one recites "Hashiveinu...” in Shemonah Esrei and asks to do teshuva, he should think that this is the moment of teshuva that Chazal say is better than all of Olam Haba.
With One Second of Teshuva One Can Reach Great Heights:
The Magid of Mezheritch zy"a (quoted in Sefer Mayan Hachochmah, Parshas Mishpatim) states that the word "sha'ah" (an hour) can also mean to turn to face something (as in Bereishis 4:5). Accordingly, the Gemara is saying that if one turns to Hashem for one moment of enthusiastic teshuva, he can reach a very lofty level and "acquire an entire world".