Those who have humility are open to things greater than themselves while those who lack it are not. That is why those who lack it make you feel small while those who have it make you feel enlarged.
Bnei Yisrael arrived at Mt. Sinai with an encampment that is famously described as “like one man with one heart” (Rashi, Shemot 19:2). The unity, which was preparatory for the receiving of the Torah, is not just preparation but is the essence of the Torah. Unity in the world and in interpersonal relationships is not just a convenient means. It is the purpose and the essence of life for all that breathes.