Read Philippians 2:5-11.
Let the same mind be in you that was in Christ Jesus, who, though he was in the form of God, did not regard equality with God as something to be exploited, but emptied himself, taking the form of a slave, being born in human likeness. And being found in human form, he humbled himself and became obedient to the point of death—even death on a cross. (Philippians 2:5-8)
Read some or all of Luke 22:14-23:56. Look for humility in Jesus' words and actions.
Is it possible for us to empty ourselves in the way that Jesus did? We aren’t God, so there is less to empty. But Paul says “let the same mind be in you that was in Christ Jesus.” How do we “let” this complete, all-encompassing humility be in us?
The unknown author of the Cloud of Unknowing in chapter 13 says that there are two things that bring about humility in us: knowledge of ourselves and knowledge of God. Of this knowledge of ourselves, of “the filth, the wretchedness, and the frailty of man, into the which we are fallen by sin,” we can learn something by self-examination. This knowledge should remain in us in some part as long as we live. The other is the knowledge of the “over-abundant love and worthiness of God himself, in view of which all nature quakes, all scholars are fools, and all saints and angels blind—so much so that if God in his wisdom did not graciously limit their ability to see according to their nature, I cannot say what would happen to them.” We see something of God’s glory, and suddenly being humble is not a problem. At all.
According to this author, it is the second cause of humility that it will last into eternity. The first cause ends at the end of this life, but it may happen that even in this mortal body, for abundance of grace, we “suddenly and perfectly forget all knowing and feeling of being.” And in that time we “are perfectly humbled, for we know and feel no cause but the Chief. And when we know and feel any other cause, even if God is the chief cause, yet it is imperfect humility.”
All Christians should learn humility by knowledge of self. It is impossible for a sinner to get and keep perfect humility without this imperfect humility. Therefore we should “swink and sweat” and strain ourselves in every way to gain a knowledge of ourselves as we are. This author states that “I believe that soon after you shall have a true knowing and feeling of God as he is—not as he is in himself,” but as is possible in this mortal body. This author says what he says about perfect humility to let us see the value of the exercise he recommends, that a secret love for God “pressed in cleanness of spirit upon this dark cloud of unknowing between you and your God, truly contains in it the perfect virtue of humility without any special or clear vision of anything under God.”
For it often happens that when we have a little knowledge and feeling of imperfect humility, we may think we have almost achieved perfect humility, and thus deceive ourselves, though we are yet filled with “foul stinking pride.” Therefore strive for perfect humility, because those who have it, while they have it, “shall not sin, nor yet much after.”
Therefore if we are completely dedicated to God, if we know something of our “filth and wretchedness” and are seeking to root it out, if we are called to greater knowledge of God, we should put our effort not into examining ourselves and dredging up sin but into seeking God, into “pressing in cleanness of spirit upon this dark cloud of unknowing” between us and our God. It is through knowing God that we receive perfect humility. It is through loving God that we come to know him. It is through seeking him that we come to love him.
What to do if that desire is weak, if we don’t seek him as we ought? Ask God for more love. God loves to give gifts, and the gift he most loves to give is love, for it is the gift of himself. Lord, increase our love.
See also The Cloud of Unknowing on CCEL. Or, for a more modern translation see the Paulist Press edition (1981).