Perhaps the most special day in Elul is the eighteenth day of Elul, Chai (which means ‘alive’) Elul. This day is the birthday of the originator of Chassidut, the Ba’al Shem Tov, and 47 years later, of the Alter Rebbe, author of the Tanya and the first Rebbe of Chabad. The Alter Rebbe was the disciple of the disciple – the spiritual grandson – of the Ba’al Shem Tov. Both have a common mazal, which is a common birthday.
The Ba’al Shem Tov himself said that the meaning of my birthday, Chai 18 Elul, is that G-d sent my soul to descend to earth in order to bring joy and liveliness into the spiritual service of the month of Elul.
The service of Elul is teshuvah, returning to G-d. It used to be done with sorrow, with tears and bitterness. Now, says the Ba’al Shem Tov, we have to undergo a spiritual transformation. Now, our return to G-d must be an experience of joy, of closeness to Him. In Kabbalah and Chassidut this is referred to as the higher level of teshuvah.
This is the call of our times, just before Mashiach. That is why the Ba’al Shem Tov was born on Chai Elul, to bring that spiritual, enlivening, joyous experience of returning to G-d into the month of Elul.