C.S. Lewis, one of the most influential Christian writer of the twentieth century, once wrote that "the essential vice, the utmost evil, is Pride. (It is) not only enmity between man and man, but enmity to God." (Mere Christianity, 1952)
The song from Casting Crowns entitled "Who Am I" elaborates a virtue that stands exactly in opposite with Pride: Humility. The song beautifully unpacks several facets of Humility and let the listeners to ponder upon the fact that Pride has stealthily crawled itself into the very center of humans' heart. Humility, in the way this song looks at it, is a God-centered manifestation to personally entrust oneself to the Most High through a growing appreciation of God's grace and an increasing understanding of humans' vice.
Firstly, the song starts out with a simple question "Who Am I?", and then goes at length to explain the extent of God's gracious deeds to the subject. Notice that the whole paragraph (all the entire song for that matters) maintains its focus on God, not on the subject; There is not even a sheer effort to explain the eminence and virtues that the subject may possess. Humility, seen from this light, is not self-centered; it does not marvel at what the self has done nor it basks in self-glory. Humility means the others take precedence. Add to that is the repetitive "Who am I" which really highlights the humility that the self has. It does not mean that one should think lowly of himself, but that even his proudest achievement or whatever factors one uses to define success pale in comparison with God's gracious and selfless deeds. 
Secondly, the only explanatory effort on the subject is delivered figuratively and all portray the ephemeral and short-lived kind of life. It looks at how temporal the life that one has, that all accomplishments actually amounts to nothing in the end; it brings to attention how broken and flawed the misdemeanor that one commits on an ongoing basis. A flower would not gaze on its own beauty if it knew that tomorrow it would die or if it knew that apart from its carer, it is just a piece of worthless seed. Along the same line, humility involves admitting that one is nothing without God's gracious intervention and understanding that even with the temporal state-of-life, all accomplishments comes only from God whose hands mercifully and relentlessly shower the self with love. 
Lastly, the song firmly ends with a personal declaration that "I am yours". After conceding that all iniquities and limitations render human helpless, one has literally no option beside surrendering faithfully to the firm and loving hands of God. It is also important to note that this is not a self-proclamation, the claim can only happen after God's initiative affirmation (and you've told me who I am), that He is the one who initiate to look and reclaim human back and that human is acting as the recipient of His loving action. Humility takes pride on the fact that one is not in control over a single thing, and that the only appropriate response to life is to rely on what God has done and to entrust one's whole being comprehensively. In conclusion, the first step to counter Pride is through Humility, and this song exposes several facets of humility on which my sin nature most of the time still prevail. Humility involves diverting the mind from the self, marveling at God's grace, conceding one's wickedness and then entrusting life into God's unfailing love. I believe that this is what Jesus meant when he said in John 15:5,
"I am the vine; you are the branches. If a man remains in me and I in him, he will bear much fruit; apart from me, you can do nothing."
