Today is 499th anniversary of the Reformation, or at least its iconic start – the nailing of Luther’s 95 theses. In the course of writing Why the Reformation Still Matters and Rediscovered Joy: Exploring the Dynamics Power of the Reformation in Galatians (forthcoming) I came across this ‘glossary’ written by Luther in the preface to his commentary on Romans. It’s a great guide to both understanding Paul and the heart of Luther’s theology.
You must not understand the word ‘law’ here in human fashion, i.e., a regulation about what sort of works must be done or must not be done. That’s the way it is with human laws: you satisfy the demands of the law with works, whether your heart is in it or not. God judges what is in the depths of the heart. Therefore his law also makes demands on the depths of the heart and doesn’t let the heart rest content in works; rather it punishes as hypocrisy and lies all works done apart from the depths of the heart. All human beings are called liars (Psalm 116), since none of them keeps or can keep God’s law from the depths of the heart. Everyone finds inside himself an aversion to good and a craving for evil. Where there is no free desire for good, there the heart has not set itself on God’s law. There also sin is surely to be found and the deserved wrath of God, whether a lot of good works and an honourable life appear outwardly or not.
Therefore in chapter 2 St. Paul adds that the Jews are all sinners and says that only the doers of the law are justified in the sight of God. What he is saying is that no one is a doer of the law by works. On the contrary, he says to them, ‘You teach that one should not commit adultery, and you commit adultery. You judge another in a certain matter and condemn yourselves in that same matter, because you do the very same thing that you judged in another.’ It is as if he were saying, ‘Outwardly you live quite properly in the works of the law and judge those who do not live the same way; you know how to teach everybody. You see the speck in another’s eye but do not notice the beam in your own.’
Outwardly you keep the law with works out of fear of punishment or love of gain. Likewise you do everything without free desire and love of the law; you act out of aversion and force. You’d rather act otherwise if the law didn’t exist. It follows, then, that you, in the depths of your heart, are an enemy of the law. What do you mean, therefore, by teaching another not to steal, when you, in the depths of your heart, are a thief and would be one outwardly too, if you dared. (Of course, outward work doesn’t last long with such hypocrites.) So then, you teach others but not yourself; you don’t even know what you are teaching. You’ve never understood the law rightly. Furthermore, the law increases sin, as St. Paul says in chapter 5. That is because a person becomes more and more an enemy of the law the more it demands of him what he can’t possibly do.
In chapter 7 St. Paul says, ‘The law is spiritual.’ What does that mean? If the law were physical, then it could be satisfied by works, but since it is spiritual, no one can satisfy it unless everything he does springs from the depths of the heart. But no one can give such a heart except the Spirit of God, who makes the person be like the law, so that he actually conceives a heartfelt longing for the law and henceforward does everything, not through fear or coercion, but from a free heart. Such a law is spiritual since it can only be loved and fulfilled by such a heart and such a spirit. If the Spirit is not in the heart, then there remain sin, aversion and enmity against the law, which in itself is good, just and holy.
You must get used to the idea that it is one thing to do the works of the law and quite another to fulfil it. The works of the law are every thing that a person does or can do of his own free will and by his own powers to obey the law. But because in doing such works the heart abhors the law and yet is forced to obey it, the works are a total loss and are completely useless. That is what St. Paul means in chapter 3 when he says, ‘No human being is justified before God through the works of the law.’ From this you can see that the schoolmasters [the Medieval scholastic theologians] and sophists are seducers when they teach that you can prepare yourself for grace by means of works. How can anybody prepare himself for good by means of works if he does no good work except with aversion and constraint in his heart? How can such a work please God, if it proceeds from an averse and unwilling heart?
But to fulfil the law means to do its work eagerly, lovingly and freely, without the constraint of the law; it means to live well and in a manner pleasing to God, as though there were no law or punishment. It is the Holy Spirit, however, who puts such eagerness of unconstained love into the heart, as Paul says in chapter 5. But the Spirit is given only in, with, and through faith in Jesus Christ, as Paul says in his introduction. So, too, faith comes only through the word of God, the Gospel, that preaches Christ: how he is both Son of God and man, how he died and rose for our sake. Paul says all this in chapters 3, 4 and 10.
That is why faith alone makes someone just and fulfils the law; faith it is that brings the Holy Spirit through the merits of Christ. The Spirit, in turn, renders the heart glad and free, as the law demands. Then good works proceed from faith itself. That is what Paul means in chapter 3 when, after he has thrown out the works of the law, he sounds as though the wants to abolish the law by faith. No, he says, we uphold the law through faith, i.e. we fulfil it through faith.
‘Sin’ in the Scriptures means not only external works of the body but also all those movements within us which bestir themselves and move us to do the external works, namely, the depth of the heart with all its powers. Therefore the word ‘do’ should refer to a person’s completely falling into sin. No external work of sin happens, after all, unless a person commit himself to it completely, body and soul. In particular, the Scriptures see into the heart, to the root and main source of all sin: unbelief in the depth of the heart. Thus, even as faith alone makes just and brings the Spirit and the desire to do good external works, so it is only unbelief which sins and exalts the flesh and brings desire to do evil external works. That’s what happened to Adam and Eve in Paradise (Genesis 3).
That is why only unbelief is called sin by Christ, as he says in John 16, ‘The Spirit will punish the world because of sin, because it does not believe in me.’ Furthermore, before good or bad works happen, which are the good or bad fruits of the heart, there has to be present in the heart either faith or unbelief, the root, sap and chief power of all sin. That is why, in the Scriptures, unbelief is called the head of the serpent and of the ancient dragon which the offspring of the woman, i.e. Christ, must crush, as was promised to Adam (Genesis 3).
Grace and gift
‘Grace’ and ‘gift’ differ in that grace actually denotes God’s kindness or favour which he has toward us and by which he is disposed to pour Christ and the Spirit with his gifts into us, as becomes clear from chapter 5, where Paul says, ‘Grace and gift are in Christ, etc.’ The gifts and the Spirit increase daily in us, yet they are not complete, since evil desires and sins remain in us which war against the Spirit, as Paul says in chapter 7, and in Galatians 5. And Genesis 3 proclaims the enmity between the offspring of the woman and that of the serpent. But grace does do this much: that we are accounted completely just before God. God’s grace is not divided into bits and pieces, as are the gifts, but grace takes us up completely into God’s favour for the sake of Christ, our intercessor and mediator, so that the gifts may begin their work in us.
In this way, then, you should understand chapter 7, where St. Paul portrays himself as still a sinner, while in chapter 8 he says that, because of the incomplete gifts and because of the Spirit, there is nothing damnable in those who are in Christ. Because our flesh has not been killed, we are still sinners, but because we believe in Christ and have the beginnings of the Spirit, God so shows us his favour and mercy, that he neither notices nor judges such sins. Rather he deals with us according to our belief in Christ until sin is killed.
‘Faith’ is not that human illusion and dream that some people think it is. When they hear and talk a lot about faith and yet see that no moral improvement and no good works result from it, they fall into error and say, ‘Faith is not enough. You must do works if you want to be virtuous and get to heaven.’ The result is that, when they hear the Gospel, they stumble and make for themselves with their own powers a concept in their hearts which says, ‘I believe.’ This concept they hold to be true faith. But since it is a human fabrication and thought, and not an experience of the heart, it accomplishes nothing, and there follows no improvement.
Faith is a work of God in us, which changes us and brings us to birth anew from God (John 1). It kills the old Adam, makes us completely different people in heart, mind, senses, and all our powers, and brings the Holy Spirit with it. What a living, creative, active powerful thing is faith! It is impossible that faith ever stop doing good. Faith doesn’t ask whether good works are to be done, but, before it is asked, it has done them. It is always active. Whoever doesn’t do such works is without faith; he gropes and searches about him for faith and good works but doesn’t know what faith or good works are. Even so, he chatters on with a great many words about faith and good works.
Faith is a living, unshakeable confidence in God’s grace; it is so certain, that someone would die a thousand times for it. This kind of trust in and knowledge of God’s grace makes a person joyful, confident, and happy with regard to God and all creatures. This is what the Holy Spirit does by faith. Through faith, a person will do good to everyone without coercion, willingly and happily; he will serve everyone, suffer everything for the love and praise of God, who has shown him such grace. It is as impossible to separate works from faith as burning and shining from fire. Therefore be on guard against your own false ideas and against the chatterers who think they are clever enough to make judgements about faith and good works but who are in reality the biggest fools. Ask God to work faith in you; otherwise you will remain eternally without faith, no matter what you try to do or fabricate.
Righteousness or Justice
‘Righteousness’ means precisely the kind of faith we have in mind, and should properly be called ‘divine righteousness’, the righteousness which holds good in God’s sight, because it is God’s gift, and shapes a man’s nature to do his duty to all. By his faith, he is set free from sin, and he finds delight in God’s commandments’. In this way, he pays God the honour that is due to Him, and renders Him what he owes. He serves his fellows willingly according to his ability, so discharging his obligations to all men. Righteousness of this kind cannot be brought about in the ordinary course of nature, by our own free will, or by our own proper powers. No one can give faith to himself, nor free himself from unbelief; how, then, can anyone do away with even his smallest sins? It follows that what is done in the absence of faith on the one hand, or in consequence of unbelief in the other, is naught but falsity, self-deception, and sin (Romans 14), no matter how well it is gilded over.
Flesh and Spirit
You must not understand ‘flesh’ here as denoting only unchastity [moral or sexual impurity] or ‘spirit’ as denoting only the inner heart. Here St. Paul calls flesh (as does Christ in John 3) everything born of flesh, i.e. the whole human being with body and soul, reason and senses, since everything in him tends toward the flesh. That is why you should know enough to call that person ‘fleshly’ who, without grace, fabricates, teaches and chatters about high spiritual matters. You can learn the same thing from Galatians 5 where St. Paul calls heresy and hatred works of the flesh. And in Romans 8 he says that, through the flesh, the law is weakened. He says this, not of unchastity, but of all sins, most of all of unbelief, which is the most spiritual of vices.
On the other hand, you should know enough to call that person ‘spiritual’ who is occupied with the most outward of works as was Christ, when he washed the feet of the disciples, and Peter, when he steered his boat and fished. So then, a person is ‘flesh’ who, inwardly and outwardly, lives only to do those things which are of use to the flesh and to temporal existence. A person is ‘spirit’ who, inwardly and outwardly, lives only to do those things which are of use to the spirit and to the life to come.
Unless you understand these words in this way, you will never understand either this letter of St. Paul or any book of the Scriptures. Be on guard therefore against any teacher who uses these words differently, no matter who he be, whether Jerome, Augustine, Ambrose, Origen or anyone else as great as or greater than they.
 The translation of this paragraph is by Bertram Lee Woolf and is taken from John Dillenberger (ed.), Martin Luther: Selections from His Writings, Anchor Books, 1961, 24-25.