When Luther responded to Erasmus’ insistence on free will he argued from where the eschatological pinch of the law sorted out the distinction between law and the Gospel – in the preaching of Christ crucified and resurrected pro me, pro nobis.
As Klaus Schwarzwaeller offered, Luther’s work in The Bondage of the Will was concerned about salvation only. Luther asked “radically and exclusively for God alone and his will, i.e. the God for us and the Gospel exclusively. ‘Solus Christus’ is carried almost to the extreme, since ‘all humankind is in need of salvation.’” In the proclamation of the Cross, Luther understood that the law was put to an end, put to death, and in its place Christ was raised from the dead. For Luther, “to will the law and the gospel, to unwill sin and to will death belongs to divine power alone, as Paul says in more than one place.”
Erasmus’ primary premise was the fundamental problem for Luther. For Erasmus, “the will always seems to be that neutral gear in an automobile which can be shifted this way and that ‘at will.’ This, Luther insisted, was mere abstraction, a logical fiction. A will, to be a will, always wills something, either good or evil.” Human disaffection with God, assuming choice and neutrality, will always make the error of assuming there is a free will.
“The truth is rather as Christ puts it: ‘He that is not with me is against me’ (Matt. 12.30). He does not say: he that is not with me is not against me either, but in an intermediate position! For if God is in us, Satan is out of us, and then it is present with us to will only good. But if God is not in us, Satan is, and then it is present with us to will only evil. Neither God nor Satan permits there to be in us mere willing in the abstract; but as you rightly said, we have lost our freedom and are forced to serve sin – that is, we will sin and evil, we speak sin and evil, we do sin and evil!”
Luther understood when the Word of God came it did not offer sinners a choice. When Christ came an eschatological battle took place between God and sinful humanity. As Luther put it, “whenever the word of God comes into the world, sinners grow worse the more they are instructed.” In fact the preaching of the Gospel only intensified the battle, “hastening the wrath of God, just as the Flood was hastened then, for it not only means that sin is committed but also that grace is despised, as Christ said, ‘When the light comes, men hate the light.”
“Now,” Luther asked Erasmus, “since, on God’s own testimony, men are flesh, they can savour of nothing but the flesh; therefore, ‘free-will’ can avail only to sin. And if, while the Spirit of God is calling and teaching among them, they go from bad to worse, what could they do when left to themselves, without the Spirit of God?” Christ Jesus must come under the form of the opposite, in exactly the opposite way the human will might want or expect. This is the way it had to be. There was no way to get through to creatures bound up by sin other than indirectly. The human free will could not suffer God but only savor the things of the flesh. Thus, for Luther, when Jesus came close, sinners wanted nothing to do with that sort of God, so they killed him.
“You, who imagine the human will as something standing on neutral ground and left to its own devices, find it easy to imagine that there can be an endeavor of the will in either direction, because you think of both God and the devil as a long way off, as if they were only observers of that immutable free will; for you do not believe that they are the movers and inciters of a servile will, and engaged in most bitter conflict with one another… For either the kingdom of Satan in man means nothing, and then Christ must be a liar, or else, if his kingdom is as Christ describes it, free choice must be nothing but a captive beast of burden for Satan, which can only be set free if the devil is first cast out by the finger of God.”
Erasmus’ problem with God was that God did not wait for sinners to work with him in matters pertaining to salvation. He did something by coming in Christ to reconcile the world to Himself.