I recommend you buy the book, if you don't have it. I think it belongs in the Essential Lutheran Library.
I've always meant to have this section handy. The highlighting of there being no Law in the conscience and the limit of the Law are my own.
For although the Law is the best of all things in the world, it still cannot bring peace to a terrified conscience but makes it even sadder and drives it to despair. For by the Law sin becomes exceedingly sinful. (Rom. 7:13)
Therefore the afflicted conscience has no remedy against despair and eternal death except to take hold of the promise of grace offered in Christ, that is, this righteousness of faith, this passive or Christian righteousness, which says with confidence: "I do not seek active righteousness. I ought to have and perform it; but I declare that even if I did have it and perform it, I cannot trust in it or stand up before the judgment of God on the basis of it. Thus I put myself beyond all active righteousness, all righteousness of my own or of the divine Law, and I embrace only that passive righteousness which is the righteousness of grace, mercy, and the forgiveness of sins." In other words, this is the righteousness of Christ and of the Holy Spirit, which we do not perform but receive, which we do not have but accept, when God the Father grants it to us through Jesus Christ.
As the earth itself does not produce rain and is unable to acquire it by its own strength, worship, and power but receives it only by a heavenly gift from above, so this heavenly righteousness is given to us by God without our work or merit. As much as the dry earth of itself is able to accomplish in obtaining the right and blessed rain, that much can we men accomplish by our own strength and works to obtain that divine, heavenly, and eternal righteousness. Thus we can obtain it only through the free imputation and indescribable gift of God. Therefore the highest art and wisdom of Christians is not to know the Law, to ignore works and all active righteousness, just as outside the people of God the highest wisdom is to know and study the Law, works and active righteousness.
It is a marvelous thing and unknown to the world to teach Christians to ignore the Law and to live before God as though there were no Law whatever. For if you do not ignore the Law and this direct your thoughts to grace as though there were no Law but as though there were nothing but grace, you cannot be saved. "For through the Law comes knowledge of sin" (Rom. 3:20). On the other hand, works and the performance of the Law must be demanded in the world as though there were no promise or grace. This is because of the stubborn, proud, and hardhearted, before whose eyes nothing must be set except the Law, in order that they may be terrified and humbled. For the Law was given to terrify and kill the stubborn and to exercise the old man. Both words must be correctly divided, according to the apostle (2 Tim. 2:25 ff).
... This is our theology, by which we teach a precise distinction between these two kinds of righteousness, the active and the passive, so that morality and faith, works and grace, secular society and religion may not be confused. Both are necessary, but both must be kept within their limits. Christian righteousness applies to the new man, and the righteousness of the law applies to the old man, who is born of flesh and blood. Upon this latter, as upon an ass, a burden must be put that will oppress him. He must not enjoy the freedom of the spirit or of grace unless he has first put on the new man by faith in Christ, but this does not happen fully in this life.
... Then do we do nothing and work nothing in order to obtain this righteousness? I reply: Nothing at all. For this righteousness means to do nothing, to hear nothing, and to know nothing about the Law or about works but to know and believe only this: that Christ has gone to the Father and is now invisible; that He sits heaven at the right hand of the Father, not as a Judge but as one who has been made for us wisdom, righteousness, sanctification, and redemption from God (1 cor. 1:30); in short, that He is our High Priest, interceding for us and reigning over us and in us through grace. Here one notices no sin and feels no terror or remorse of conscience. Sin cannot happen in this christian righteousness; for where there is no Law, there cannot be any transgression (Romans 4:15). If, therefore, sin does not have a place here, there is no conscience, no terror, no sadness. Therefore John says: "No one born of God commits sin" (1 John 3:9). But if there is any conscience or fear present, this is a sign that this righteousness has been withdrawn, that grace has been lost sight of, and that Christ is hidden and out of sight. But where Christ is truly seen, there must be full and perfect joy in the Lord and peace of heart, where the heart declares: "Although I am a sinner according to the Law, judged by the righteousness of the Law, nevertheless I do not despair. I do not die, because Christ lives who is my righteousness and my eternal and heavenly life. In that righteousness and life I have no sin, conscience, and death. I am indeed a sinner according to the present life and its righteousness, as a son of Adam where the Law accuses me, death reigns and devours me. But above this life I have another righteousness, another life which is Christ the Son of God who does not know sin and earth but is righteousness and eternal life. For His sake this body of mine will be raised form the dead and delivered from the slavery of the Law and sin, and will be sanctified together with the spirit."
Thus as long as we live here, both remain. The flesh is accused, exercised, saddened, and crushed by he active righteousness of the Law. But the spirit rules, rejoices, and is saved by passive righteousness, because it knows that it has a Lord sitting in heaven at the right hand of the Father, who has abolished the Law, sin, and death, and has trodden all evils underfoot, has led them captive and triumphed over them in Himself (Co. 2:15). In this epistle, therefore, Paul is concerned to instruct, comfort, and sustain us diligently in a perfect knowledge of this most excellent and Christian righteousness. For if the doctrine of justification is lost, the whole of Christian doctrine is lost. And those in the world who do not teach it are either Jews or Turks or papists or sectarians. For between these two kinds of righteousness, the active righteousness of the Law and the passive righteousness of Christ, there is no middle ground. Therefore he who has strayed away from this Christian righteousness will necessarily relapse into the active righteousness; that is, when he has lost Christ, he must fall into a trust in his own works.
We see this today in the fanatical spirits and sectarians, who neither teach nor can teach anything correctly about this righteousness of grace... They cling only to the righteousness of the Law. Therefore they are and remain disciplinarians of works; nor can they rise beyond the active righteousness. Thus they remain exactly what they were under the pope.
...Therefore we always repeat, urge and inculcate this doctrine of faith or christian righteousness, so that it may be observed by continuous use and may be precisely distinguished from the active righteousness of the Law. (For by this doctrine alone and through it alone is the church built, and in this it consists.) Otherwise we shall not be able to observe true theology but shall immediately become lawyers, ceremonialists, legalists, and papist.
... In affliction and in the conflict of conscience it is the devil's habit to frighten us with the Law and to set against us the consciousness of sin, our wicked past, the wrath and judgment of god, hell and eternal death, so that thus he may drive us into despair, subject us to himself, and pluck us from Christ. It is also his habit to set against us those passages in the Gospel in which Christ Himself requires works from us and with plain words threatens damnation to those who do not perform them. If here we cannot distinguish between these two kinds of righteousness; if here by faith we do not take hold of Christ, who is sitting at the right hand of God, who is our life and our righteousness, and who makes intercession for us miserable sinners before the Father (Heb. 7:25), then we are under the law and not under grace, and Christ is no longer a Savior. Then He is a lawgiver. Then there can be no salvation left, but sure despair and eternal death will follow.
Therefore let us learn diligently this art of distinguishing between these two kinds of righteousness, in order that we may know how far we should obey the law. We have said above that in a Christian the Law must not exceed its limits but should have its dominion only over the flesh, which is subjected to it and remains under it. When this is the case, the law remains within its limits. But if it wants to ascend into the conscience and exert its rule there, see to it that you are a good dialectician and that you make the correct distinction. Give no more to the Law than it has coming, and say to it: "Law, you want to ascend into the realm of conscience and rule there. You want to denounce its sin and take away the joy of my heart, which I have through faith in Christ. You want to plunge me into despair, in order that I may perish. You are exceeding your jurisdiction. Stay within your limits, and exercise your dominion over the flesh. You shall not touch my conscience. For I am baptized; and through the gospel I have been called to a fellowship of righteousness and eternal life, to the kingdom of Christ, in which my conscience is at peace, where there is no Law but only the forgiveness of sins, peace, quiet, happiness, salvation, and eternal life. Do not disturb me in these matters. In my conscience not the Law will reign, that hard tyrant and cruel disciplinarian, but Christ, the Son of God, the King of peace and righteousness, the sweet Savior and Mediator.
... When I have this righteousness within me, I descend from heaven like the rain that makes the earth fertile. That is, I come forth into another kingdom, and I perform good works whenever the opportunity arises. If I am a minister of the Word, I preach, I comfort the saddened, I administer the sacraments. If I am a father, I rule my household and family, I train my children in piety and honesty. If I am a magistrate, I perform the office which I have received by divine command. If I am a servant, I faithfully tend to my master's affairs. In short, whoever knows for sure that Christ is this righteousness not only cheerfully and gladly works in his calling but also submits himself for the sake of love to magistrates, also to their wicked laws, and to everything else in this present life--even, if need be, to burden and danger. For he knows that God wants this and that this obedience pleases Him.
(Luther's commentary on the Epistle to the Galatians. 1535. Luther's Works. Volume 26. American Edition. The Argument of St. Paul's Epistle to the Galatians. pp. 4-12)
And if you are myself, and it is summer, finally, and your relatives are all coming and there is work everywhere, you might get off the computer and get your head out of the books and get something done, i.e. I shall take a break from this at least until after the wedding.