Today is the fast of Tammuz. The 17th of Tammuz. So many calamities occurred on this day: The first tablets (the 10 commandments) were smashed and destroyed, another year the outer wall was breeched by the Romans, the daily offering ceased, etc and so on.
Another fast day is coming up which is a bigger fast day, the 9th of Av, Tisha b'Av. Also during that time much calamities befell the Jewish people. The spies came back with a discouraging report on Israel, the Temples were destroyed, Bar Kochba's hideout was discovered and he was taken by the Romans, etc and so forth.
To me there is something related inside all the calamities: for the ones in Tammuz, it seems that it had to do with a lapse of Daat /knowledge of the Holy One. They thought Moshe died up on the mountain trying to bring down the Torah. So they figured they make for themselves a new idol, the golden calf. It is as if this created a dent or a cavity in time. A hole in which Hashem's countenance is turned away. And when Hashem's countenance is turned away...calamities happen.
In the case of Tisha b'Av, it seems to be a lapse of faith. Their hopes were dahsed when the spies reported how huge the people of Kanaan were. Seeing the Holy Temples --the physical mantra of prayer-- set on fire by the Romans was disheartening. And their herok Bar Kochba being flushed out by the Romans and tortured and killed again is very disheartening. All this from the hole that was created from the very first incident --the spies report bringing the people to dispair.
Just like a tooth when exposed to too much sugar or bacteria gets a cavity, so too time was exposed to too great a degeneration --a break even within the basic truth-- and it caused a hole in time.
Most dentist would like you to think that once there is a cavity, there is no choice but to rush to the dentist and get it filled with mercury or other substance. However, there is a small voice that says that one's tooth can be regenerated, remineralized and repaired!
This hole in time also doesn't have to be simply filled with nothing. It can be repaired. By holding on to truth and never letting that line get breached, we can insure that neither another Tammuz calamity nor an Av calamity befall us. As long as we keep revolving around (1) improving our daat /knowledge of Hashem and (2) renewing our fath when things go wrong and never, ever crashing down to the point of even wondering if there is a G-d (back to square one!) there is hope!
Hope you have an easy fast.