You are such an accursed, ungrateful wretch that you will not give a child into training for the maintenance of the gifts of God. You have everything, all of it free of charge; yet you show not a particle of gratitude. Instead you let God's kingdom and the salvation of people's souls go to ruin; you even help to destroy them. Ought not God to be angry over this? Ought not famine to come? Ought not pestilence, flu, and syphilis find us out? Ought not blind, fierce, and savage tyrants come to power? Ought not war and contention arise? Ought not evil regimes appear in our lands? Ought not our enemies plunder us? Indeed, it would not be surprising if God were to open the doors and windows of hell and pelt and shower us with nothing but devils, or let brimstone and hell-fire rain down from heaven and inundate us one and all in the abyss of hell, like Sodom and Gomorrah.
From A Sermon on Keeping Children in School, pg. 254 of Luther's Works, Vol. 46