Nearly 2,000 years ago the 2nd Temple in Jerusalem was destroyed. The Jewish people were forced to scatter across the globe, banished from their beloved Land of Israel. Why? Was it a coincidence?
The destruction of the Temple is a phase in the rebuilding of the 3rd temple. Without a destruction, the pinnacle the third Temple shall reach could not be attainable. As a necessary prerequisite to rise well beyond the previous level of holiness, a descent was a necessary component to achieve the ultimate ascent, as sure as a seed must first decompose to become a tree. The first two Temples were built by human hands. The third Holy Temple will be built by God, with only about 1% of it left for finishing by man. But to merit this final and eternal Temple, Jews had to undergo exile for nearly two millennia, to wrought a refinement that only an exile, a long exile, can accomplish.
Nevertheless, despite the role the exile has on the Jewish spirit, the Jewish presence in all countries they exist across the globe - has another purpose too. And that is to raise the people around them to higher spiritual levels as well. When Abraham began his life in the Middle East, he was the sole person in the entire world who recognized the One and Only God of the universe. Since his time, many more have come to recognize what to Jewish people is today obvious. However, even today, no more than a third, I reckon, of people the world over recognize and believe in the One and Only God, and this is sad.
The Jewish people also have influenced their Gentile peers in many other respects and have changed their values exceedingly. Look at the world today, in terms of peaceful countries living side by side, with defined borders, with humanitarian respect for each other, and realize that this phenomenon of borders more than a hundred years ago never existed. Then the law of might held sway and borders were as fluid as were the armies they encompassed.
The Jewish people are a light to all nations and the foremost light with which they illuminate comes from the Torah. Without the light of Torah, for example, the dream and manifest creation of the free land of America would never have happened. The founding fathers in this land of liberty, and every great American today who espouses love of God, love of freedom and love of country, have been touched by Jewish Torah values.
Tisha B'Av for Jews is a day of mourning for on this calendar day the destruction of both Temples occurred. But it is also the day the supernal light impregnating this darkness took conception. The destruction was not for its own sake but rather for the sake of a higher, positive result. That's why on that day the birth of Moshiach's light came into being. It is the brightest light yet to shine, and glimmers of it are breaking through the fog of a turbulent world, at least for those whose eyes are keenly focused to the teachings of our sages and rabbis. This bright light will soon shine upon the earth, will raise the earth by orders of magnitude in spirituality, will reward the good people with this new insight, it will sweep away evil and will bring on the utopia this day was meant for in the first place - may it happen very soon, in our own days.