And judge me by Thy strength. This again leads us to the same results. What is the strength of God by which He saves us? It is that which is a stumbling block to the Jews and folly to the Gentiles. It is weakness, suffering, cross, persecution, etc. These are the weapons of God, these the strengths and powers by which He saves and judges us and distinguishes us from those who think otherwise. For according to the apostle, in 1 Cor. 1:25, “the weakness of God is stronger than men, and the foolishness of God is wiser than men.” [“The Gospel is the power of God unto salvation to everyone who believes” (Rom. 1:16).] For this the world does not know, that patience, humility, cross, and persecution are strength and wisdom. Hence it is judged on this point and by its ignorance is distinguished from the saints, to whom Christ crucified is strength and wisdom; for through the cross and suffering that is both theirs and His they triumph over every force of the devil. Therefore this is truly God’s power, and yet it is the weakness of men. For He has chosen what is weak to confound what is strong.
Luther’s works, vol. 10: First Lectures I