This gem from Luther was cited in the Holy Trinity 2013 issue of Logia: A Journal of Lutheran Theology. He is commenting on Psalm 32:8, giving to us God's perspective on suffering:
"You ask that I deliver you. Then do not be uneasy about it; do not teach me, and do not teach yourself; surrender yourself to me. I am competent to be your Master. I will lead you in a way that is pleasing to me. You think it wrong if things do not go as you feel they should. But your thinking harms you and hinders me. Things must go, not according to your understanding but above your understanding. Submerge yourself in a lack of understanding, and I will give you my understanding. Lack of understanding is real understanding; not knowing where you are going is really knowing where your are going. My understanding makes you without understanding... Behold, this is the way of the cross. You cannot find it, but I must lead you like a blind man. Therefore not you, not a man, not a creature, but I, through my Spirit and the Word, will teach you the way you must go." (AE 14:152)
This is the theology of the cross at its finest; our human reason understanding and will must be placed in servitude and instead in childlike faith, God calls on us to trust His understanding and His will. When we cry on Him to save us, we give up on our own ability to save ourselves. A lack of understanding, but yet faith in the Lord's promises, is real understanding.