How Important Is Jewish Unity?

Derech Hashem says that if all the Jewish people would be united as one nation, with one opinion, they would bring down the Shechinah just like at the giving of the Torah. The Torah says, "He camped" at Har Sinai, and the Gemara says "he" refers to the Jewish people. They became like one person, and because there were six hundred thousand people all in one place, the largest amount of Shechinah possible came down at that time. Avraham, Yitzchak and Yaacov didn't merit that. As noble as they were, they were not a multitude. When Jews come together, united for Hashem, the Shechinah comes down on them. That took place at Har Sinai and remained with us forever; we became Yisrael from that point on. While the nations of the world fell at that time, the Jewish people became greater. -- The Truth of the Torah