Anyway, this is what your words assert; that there is strength within us; there is such a thing as striving with all one’s strength; there is mercy in God; there are ways of compassing that mercy…But if one does not know what this ‘strength’ is—what men can do, and what is done to them—what this ‘striving’ is, what men can do, and what is done to them—then what should he do? What will you tell him to do?…For as long as they do not know the limits of their ability, they will not know what they should do; and as long as they do not know what they should do, they cannot repent when they err; and impenitence is the unpardonable sin…So it is not irreligious, idle, or superfluous, but in the highest degree wholesome and necessary, for a Christian to know whether of not his will has anything to do in matters pertaining to salvation. Indeed, let me tell you, this is the hinge on which our discussion turns, the crucial issue between us; our aim is, simply, to investigate what ability ‘free-will’ has, in what respect it is the subject of Divine action and how it stands related to the grace of God. If we know nothing of these things, we shall know nothing whatsoever of Christianity. (The Bondage of the Will, Luther’s Reply to Erasmus)
Luther demonstrated a vast amount of insight in the above response to Erasmus’ claim that the will had some strength, but it just needed the mercy of God to help it. The historical Reformed view is that the will has no strength in it at all to do any good. It appears that Luther believed that. But notice how clearly the Gospel of grace alone stands out when it is looked at in this light. If the will has no strength, then it is grace alone that saves sinners and actually moves the will. But if the will has some strength, even just a tiny amount, then it is not grace alone that saves sinners. It is grace plus the will. This is a lesson that we moderns should pay close attention to. This should change the way we preach and practice evangelism. How can we assign power to the will either explicitly or just remain silent on the issue when there is no power in the will? We are misleading people if we do not tell them that they have no power of the will and we are not telling them what will really save them. In other words, we are telling them something less than a whole Gospel.
If the Gospel is the Gospel of grace alone, then that needs to be explained and set out clearly. As long as people think that they have power in the will to make the final decision or even make some contribution, we have not set out the Gospel of grace alone to where they understand it. This was what Jonathan Edwards did in the 1700’s and then Asahel Nettleton did so well in the early 1800’s. They strove to deliver people from any hope in themselves because they saw that as long as a person had any hope in the strength of the will that they were under a delusion. If a clear Gospel is to be taught in any age, then we must set out the strength and power of the will so that grace can be seen for what it is and what it does.
Luther points out that if a person believes that the will has some power to do certain things then that person will do them. This is precisely what the preacher sets out to destroy so that the sinner may trust in grace alone. The confidence of the sinner in his own will must be destroyed so that he can see that he has no merit and no work that will contribute to salvation. Grace saves only when it saves without any help in order that grace may be grace (Romans 11:6). As long as the sinner thinks that s/he has some power in the will or free-will to do something pertaining to salvation, s/he will do that. But as long as the sinner thinks s/he has that power of the will to do something, the sinner will never truly repent of self-sufficiency.
It must be grace in the heart enabling it to believe, trust, and love or it would not be a work of human effort. It must be grace in the soul doing this or nothing it would do would be acceptable. There is no choice that a human being can make that is full of evil intents and motives that is acceptable to God. The only thing that can move God is His own name and the unbelieving heart hates Him and all it does falls short of His glory. Yet Genesis 6:5 tells us about the state of the unbelieving heart. Its very intents and motives are evil. The unbelieving heart can do nothing that is anything else but apart from an intent to do evil with motives that are evil. The unbelieving heart cannot do one thing out of pure love. If the heart that chooses God is an unbelieving heart, it chooses with evil intents and motives. It chooses without love which is the Greatest Commandment. Teaching on the impotence of the will, therefore, is not something that is extra or makes one a hyper-Calvinist. It is something that we do in order to preach the Gospel of grace alone. If we do not teach people that their will has no power and it is grace alone that saves, then we are not preaching the Gospel of grace alone. It is vital to the biblical Gospel of God. If we don’t know these things, we know nothing whatsoever of Christianity. If we don’t teach these things to others, then they will know nothing whatsoever of Christianity. It is that vital.