‘By the law is the knowledge of sin,’ says Paul (Rom. 3:20). Here he shows how much and how far the law profits, teaching that ‘free-will’ is of itself so blind that it does not even know what sin is, but needs the law to teach it! And what can a man essay to do in order to take away sin, when he does not know what sin is? Surely this; mistake what is sin for what is not sin, and what is not sin for what is sin! Experience informs us clearly enough how the world, in the person of those whom it accounts its best and most zealous devotees if righteousness and godliness, hates and hounds down the righteousness of God preached in the gospel, and brands it heresy, error, and other opprobrious names, while flaunting and hawking its own works and devices (which are really sin and error) as righteousness and wisdom. By these words, therefore, Paul stops the mouth of ‘free-will’, teaching that by the law it is shown sin, as being ignorant of its sin; so far is he from allowing it any power to make endeavors towards good (Luther, Bondage of the Will).
The will of man is so blind that it does not know what sin is. Can the will of fallen man know what it means to repent and believe in its fallen and blind state? The will cannot know that and indeed must have the teaching of Scripture to set it out and declare it. The will of man is dark and must have the light to shine and teach it about itself and what repentance and faith truly are (is?). If we are taught by Scripture what it means to be dead in sins and trespasses, then we will know that a dead person does not have a ‘free-will.’ If we are taught by the Spirit the inward truth of what it means to be dead in sins and trespasses, then we will know that we have no power in and of ourselves to change our own hearts so that we can repent and believe.
The power to repent and believe is assuredly beyond the power of sinful man. Human souls are completely and totally in the hand of God and He must give the soul the power of life to repent and believe. But does the soul that is in darkness know that? No, when the soul that is dead in sin hears the command to repent and believe, it just assumes the Pelagian doctrine that it must have the power to do so. In other words, the human soul is in such darkness that it does not know what true repentance and faith are. It does not know its own state in death and what it would take for it to repent and believe. What is the great danger of not instructing souls about this truth?
Jonathan Edwards tells us the danger by saying this: “If you imagine that you have it in your own power to work yourselves up to repentance, consider, that you must assuredly give up that imagination before you can have repentance wrought in you” (Seeking God, International Outreach). Luther instructs us that the soul does not even know what sin is until it is instructed by the law. This tells us that until a soul knows what sin really is and the depths of its own sin and inability, then it needs to hear more of the law. Not only hear more of the law, but hear more of the law teach it of its own inability. Until a soul has reached the point of knowing that it cannot work its own repentance, it has not reached the point of looking to grace alone to work this in it.
Ephesians 2:4 But God, being rich in mercy, because of His great love with which He loved us, 5 even when we were dead in our transgressions, made us alive together with Christ (by grace you have been saved), 6 and raised us up with Him, and seated us with Him in the heavenly places in Christ Jesus, 7 so that in the ages to come He might show the surpassing riches of His grace in kindness toward us in Christ Jesus. 8 For by grace you have been saved through faith; and that not of yourselves, it is the gift of God; 9 not as a result of works, so that no one may boast. 10 For we are His workmanship, created in Christ Jesus for good works, which God prepared beforehand so that we would walk in them.
In the text above there is no hint of the ability of man, any light in man, or any ‘free-will’ in man. There is nothing but the mercy, love, grace, life, and power of God. In verses 1-3 of Ephesians 2 we see that man is dead in sins and trespasses and is under the power of the lusts of the mind and of the flesh. But starting in verse 4 it all becomes about God and what He does. God takes the dead sinners and makes them alive. It is not about the sinners ‘free-will,’ but instead it is about God’s rich mercy and great love. It is God who raises sinners from the dead and seats them with Christ. Again, we don’t see even a hint of the ability of man or of the ‘free-will’ of man. It is God that does this in order to show the riches of His grace, and yet not a word of the worth or ability of man. Is it because man works up faith so that God will do this? No, this faith itself is a gift of God. Salvation is by grace alone and not one shred of it (even the smallest of shreds) is by the will or merit of man. The Gospel is that of a God who makes sinners alive by grace, and so we must teach sinners not to trust in their own wills. It is grace alone.