Elul and Tishrei are a Preparation for Ata Hareisa:
The Rebbe of Kuzhmir zy”a (quoted in Imros Moshe) says that the Three Weeks between Shiva Asar B’Tamuz and Tisha B’Av and the day of the 15th of Av, as well as the entire month of Elul, Rosh Hashanah, the blowing of the shofar, the Aseres Yemei Teshuva, Yom Kippur and its tefillos, the days between Yom Kippur and Sukkos, the days of Sukkos and its mitzvos, and Hoshana Rabbah, are all a preparation for the recitation of “Ata Hareisa La’daas”. All of those mitzvos and avodos are a means of preparing to declare that Hashem is the only King!
A Promise to Strengthen Oneself in Torah:
Sefer Likutei Yehuda (Parshas Pinchos) quotes his grandfather, the Chidushei Harim zy”a, as saying that Rosh Hashanah and Yom Kippur are days when teshuva is done out of fear, Sukkos is a time when teshuva is done out of love and Simchas Torah is a time when we make a promise to strengthen our connection to the Torah.
