It states in this week's parashah (Bereishis 10:10) וארך בבל ממלכתו ראשית ותהי, "And the beginning of his kingdom was Bavel and Erech..." The Or L'Shamayim of Apta zt'l explained the pasuk to mean that the beginning of accepting מלכות, the yoke and kingdom of heaven is בבל, to study Talmud Bavli. And then one will merit ארך, which means long life (ימים אריכות) and health. Reb Moshe Mordechai of Lelov zt'l would often repeat this vort to remind people that the beginning of accepting the yoke of heaven is to study Gemara.
Bringing korbanos is one way of performing teshuvah. The Midrash (Shemos Rabba 38:4) tells that Bnei Yisrael say to Hakadosh Baruch Hu, "We are poor, and we don't have money to bring korbanos." Hakadosh Baruch Hu replies, "I am only asking that you give Me words. As it states (Hosheia 14:3) 'ה אל ושובו דברים עמכם קחו, 'Take words with yourselves and return to Hashem,' and I will forgive all your aveiros." The Midrash explains that "words" means תורה דברי, that they should speak words of Torah. That is how they can do teshuvah before Hashem.
Chazal (Tamid 32:) say, "Whoever studies Torah at night, כנגדו שכינה, the Shechinah is opposite him." The Beis Yisrael explained that this refers to a person who is at a low level, represented by לילה. Furthermore, כנגדו, he is rebellious against Hashem, r'l. Nevertheless, when he studies Torah, he merits that the Shechinah is with him.
Rebbe Bunim of Peshischa taught that when a person sins, his neshamah leaves. He receives his neshamah back when he studies Torah. This is hinted at in the pasuk (Tehillim 19:8) נפש משיבת תמימה 'ה תורת, with the study of Torah, נפש משיבת, the neshamah is returned to him.
Rashi (Devarim 32:46-47) teaches, "A person should direct his eyes, heart, and ears to the words of Torah... מכם הוא רק דבר לא כי, you aren't toiling in Torah for nothing, you will receive a great reward for this."
The Or HaChaim (Devarim 32:2) teaches that studying Torah is mesugal for parnassah. He writes, "If words of Torah aren’t spoken, Hashem doesn't want to send down rain to them. It states (Avos 3:17) of אין קמח אין אם תורה, this means that if you see that there isn't קמח, parnassah, know that it is due to a lack of Torah."
The following Midrash is also an indication that the process of teshuvah is to study Torah. The Midrash states (Vayikra Rabba 25:1), "If a person transgresses an aveirah, what should he do and merit life? If he was accustomed to studying one page, he should study two. If he was accustomed to study one chapter, he should study two." This is because the path of teshuvah is through studying Torah.
In Shemonah Esrei, we say אבינו השיבנו לפניך שלמה בתשובה והחזירנו ...לתורתך, "Return us, our Father, to Your Torah... and bring us back with complete teshuvah before You." The Imrei Emes zt'l notes that a tefillah for Torah study precedes the request for teshuvah because the path to teshuvah is through studying Torah. And this is because the light of the Torah will bring one to complete teshuvah (see Yalkut Yirmiyahu 282).
The Torah discusses the teshuvah that Klal Yisrael will do before Moshiach comes. It states (Devarim 30:2) בקלו ושמעת אלקיך 'ה עד ושבת, "You will return to Hashem, your G-d, and you will listen to His voice." The Or HaChaim writes, "בקולו ושמעת refers to studying Torah. The Torah doesn't mention [any other step in teshuvah, other than that he will study Torah]. This is the beginning of teshuvah. As Chazal (Zohar vol.3 270.) states, 'In the merit of studying Torah, the Yidden will be redeemed. And it states (Yirmiyahu 9:11-12) מה על תורתי את עזבם על 'ה ויאמר ,'וגו הארץ אבדה, 'Why is the land lost? Hashem said, 'It is because they have left My Torah.' When they return to the Torah study, Hashem will gather them and bring them to the land they inherited."
