The Rosh Hashana, Yom Kippur, and Succot Connection
The Baalei Mussar say that the three Yomim Tovim in Tishrei, Rosh Hashana, Yom Kippur, and Succot are all one long continuous Yom Tov, all with the purpose of fully returning to Hashem.
Rosh Hashana is the day we start this process by reflecting and contemplating where it is that we stand in our relationship with Hashem. After realizing that we are not where we should be and how far we have drifted, we spend the week between Rosh Hashana and Yom Kippur regretting and repairing the damage. On Yom Kippur Hashem forgives us and we start our relationship anew.
Succot we leave our home and go on a second honeymoon where we enjoy Hashem's company in Hashem's honeymoon getaway; alone together in the quiet of the succah, free from the distractions of the rest of the world.
Source: Revach L'Neshama