Since the 17th of Tammuz was yesterday on Shabbat, and we don't fast on Shabbat, today - Sunday the 18th of Tammuz -marks the beginning of the “Three Weeks” (Bein HaMetzarim), a period of mourning marking the destruction of both the First Temple and the Second Temple in Jerusalem. During the “Three Weeks”, it is customary to spend extra time studying Torah and in personal prayer, to give extra charity and not to hold joyous celebrations, such as weddings, or wear new clothes. We also don't listen to or play musical instruments during this period.
The first Holy Temple was destroyed because of idolatry and the 70 shemitta (Sabbatical year) cycles that were not observed, both heinous transgressions in Judaism. The punishment - 70 years of exile.
The second Holy Temple was destroyed because of baseless intramural hate, seemingly a much lesser transgression than idolatry and desecration of Sabbatical years. Yet, 2000 years have gone by and we're still in exile. When will we ever learn? Hashem despises arrogance because it leads to hate; when one person or group thinks that they're better than anyone else, that's sufficient arrogance to perpetuate the exile. The result? Another Three Weeks of lamentations.
Hashem doesn't need the lamentations of those who allow themselves the luxury of condemning, hating, snobbing and/or boycotting other Jews. Thank G-d my beloved rabbi and teacher Rav Shalom Arush is a beacon of unconditional love and demands the same of his students.
Loving another Jew doesn't mean that you necessarily agree with his practices or philosophy in life. Loving the other person is a simple commandment of Torah that Hashem unconditionally requires of all of us, to respect all others and to treat them in the same manner that we would like to be treated.
Just remember - our sages in Tikkun Chatzot (Midnight Lamentations) say that every generation who fails to rebuild the Holy Temple is as if it were the generation that destroyed it. Categorically, intramural hatred is not only perpetuating the exile, but is causing Hashem to use drastic measures to wake us up and to prod us to act like brothers toward each other. Let's start being stringent about our unconditional love for each other, so that the notorious Three Weeks will turn into Three Weeks of joy and redemption, amen!