The following is a quote from Teresa of Avila in a piece that she writes for her fellow nuns:
I was once considering what the reason was why our Lord loved humility in us so much, when I suddenly remembered that He is essentially the Supreme Truth, and that humility is just our walking in the truth. For it is a very great truth that we have no good in us, but only misery and nothingness, and he who does not understand this walks in lies: but he who understands this the best is the most pleasing to the Supreme Truth. May God grant us this favour, sisters, never to be without the humbling knowledge of ourselves.
Travels from Ur 