Chasidut על עירובין 107:34

Your love should be because you know and remember that you are all messengers of God, such that none of you can say, "I am for myself and my friends are completely secondary." Nothing depends upon you, but rather upon the One on high who sent you. You must serve with all of your strength; and Your God of hosts will raise and make each one of you great, both spiritually and physically - according to the level of his service and the level of his humility. And how many times have we been shown lads with great abilities who remained insignificant because they became haughty. Moreover, even regarding a great man who already merited to be a Torah scholar, the Sages, may their memory be blessed, said (Eruvin 54a), "If he becomes arrogant, the Holy One, blessed be He, brings him down." And how many lads have we seen who were not noteworthy as children, but became the glory of Israel as adults!