…Ask God that He keep us in His light and grace-filled Word, so that we do not fall back into such great or even greater darkness, as HE says in John 12 [:35-36]: “While you have the light, believe in the light, so that the darkness may not overtake you.” For if we are unthankful, as were our forefathers, surely God is able to punish us with a blindness just as great as that with which they were punished. Look at how the heathen, Jews, Turks, and pope are being punished with blindness. If God withdraws His hand in anger, then the prince of darkness immediately takes us to believe whatever he wants. Thus the Egyptians in former times believed that an ox, dog, fish, worm, or even onions and garlic were gods. When God’s omnipotence abandons us, then the devil is omnipotent in His place, for all men must be taken captive.
Martin Luther, Luther’s Works, American Edition, ed. Christopher Boyd Brown. vol. 60, Prefaces II, (Saint Louis: CPH, 2011) 278.