Our sages regarded the 15th of Av to be one of the two most auspicious days on the Jewish calendar (the other being Yom Kippur -- Talmud, Taanit 26b).
The world received written words from the Ruach haKodesh, to be taught and to receive encouragement of the Tanakh and presenting prophesies so that we might patiently hold on to a hope entrusted by the Most High Elohim, so that we may be fully equipped for every good work.
Historically, any Jewish group which denied the basic principles of Jewish tradition – Torah and mitzvah-observance – ultimately ceased to be part of the Jewish people. Rabbi Jeshua never denied the basic principles of Jewish tradition, though several who call themselves Christian are not following Christ his teachings and ignore even the basic Jewish core teachings and do not want to work at the basic characteristics a child of God should have. To remind us of those elements we should work at, the Elohim has given us a useful tool to remember all those basic characteristics.