Rabbi Shalom DovBer of Lubavitch said:
"We must deeply cherish the 48 hours of Shemini Atzeret and Simchat Torah. Every minute it is possible to accumulate veritable treasure houses [of blessings], physically and spiritually.
"How? By dancing."
Simchat Torah comes as a result of the spiritual service of Rosh Hashanah and Yom Kippur. For during all the days of the year we cause a deficiency and a blemish Above by not performing mitzvot correctly, and when on Rosh Hashanah and Yom Kippur we make up all the deficiencies, we feel the joy of a mitzvah.
The Baal Shem Tov once related to his students:
On Simchat Torah day we pray the morning services a little later, because of the hakafot and the festive meal the night before.
The supernal angels, who do not have this service, are preparing as usual to recite songs of praise to G-d. However, they cannot do this without the souls of the Jewish people, for the angels do not sing songs of praise Above until the Jews sing them below.
So while waiting, they occupy themselves with cleaning up
Gan Eden. To their surprise they come across worn-out shoes, which greatly amazes them, for they are used to finding tzitzit and tefillin, but not shoes.
So they approach the angel Michael to ask him about it. He answers that these are actually his merchandise and that they are from the dancing of the Jewish people with Torah scrolls. The Angel Michael then begins to count the shoes: "These are from Kaminka, these are from Mezritch..."
With these torn shoes the angel Michael glories over the angel Metat, who fashions crowns for his Creator from the prayers of the Jews, saying that he will make better crowns from these torn shoes.
--Days of Awe, Days of Joy