Working on the quality of humility is of extreme importance, since humility is the root and source of all of one's fine character traits. In fact, one who lacks humility will find it difficult to admit that he needs to improve his qualities, something that is required of every single one of us.
While we are supposed to find the middle path in the journey of refining our character traits, when it comes to humility, our Rabbis of blessed memory teach us that even small amounts of arrogance are absolutely undesired. Rather, one should aspire to achieve a pure level of humility without a shade of conceit.
We can learn an important lesson in humility when we examine the way the Holy One blessed be He acts with the world and His creations. Right at the beginning of Sefer Bereshith, before the creation of Adam and Eve, we read G-d's famous words: "Let us make a man" (Genesis, 1:26). The Holy One blessed be He consults with His retinue about the creation of man, to teach us about G-d's humility and our responsibility to emulate Him. Rashi explains that the Torah uses this form of speech, in the plural, in spite of the fact that such a statement may give an opening for the heretics to claim that this is a clear proof that there is more than one G-d, Heaven forbid.
Hakham Eliyahu HaKohen writes in Shebet Musar that the fact that G-d left the Heavens and came down to dwell on earth in the Tabernacle, was to teach us a profound lesson: the greater the person is, the more he is expected to lower himself.
Ironically, this quality is looked down upon in the outside world and is considered to be a sign of weakness. It is important to always go back to our sources and follow the guidelines of our giant Torah scholars. We, who know the real truth, understand that the more humble we are, the greater as a people we become. We know that the greatest person our Jewish nation had, was Moshe Rabbenu, 'a"h, about whom it was said: "And the man Moshe is exceedingly humble" (Bamidbar, 12:13)
Humility paves the road for real greatness.