The doctrinal contents of the entire Holy Scriptures, both of the Old and New Testaments, are made up of two doctrines differing fundamentally from each other, namely, the Law and the Gospel.
From the Book of Concord, Formula of Concord, Epitome, Article V. Law and Gospel
The Principal Question In This Controversy.
1] Whether the preaching of the Holy Gospel is properly not only a preaching of grace, which announces the forgiveness of sins, but also a preaching of repentance and reproof, rebuking unbelief, which, they say, is rebuked not in the Law, but alone through the Gospel.
Affirmative Theses: Pure Doctrine of God’s Word.
2] 1. We believe, teach, and confess that the distinction between the Law and the Gospel is to be maintained in the Church with great diligence as an especially brilliant light, by which, according to the admonition of St. Paul, the Word of God is rightly divided.
3] 2. We believe, teach, and confess that the Law is properly a divine doctrine, which teaches what is right and pleasing to God, and reproves everything that is sin and contrary to God’s will.
4] 3. For this reason, then, everything that reproves sin is, and belongs to, the preaching of the Law.
5] 4. But the Gospel is properly such a doctrine as teaches what man who has not observed the Law, and therefore is condemned by it, is to believe, namely, that Christ has expiated and made satisfaction for all sins, and has obtained and acquired for him, without any merit of his [no merit of the sinner intervening], forgiveness of sins, righteousness that avails before God, and eternal life.
6] 5. But since the term Gospel is not used in one and the same sense in the Holy Scriptures, on account of which this dissension originally arose, we believe, teach, and confess that if by the term Gospel is understood the entire doctrine of Christ which He proposed in His ministry, as also did His apostles (in which sense it is employed, Mark 1:15; Acts 20:21), it is correctly said and written that the Gospel is a preaching of repentance and of the forgiveness of sins.
7] 6. But if the Law and the Gospel, likewise also Moses himself [as] a teacher of the Law and Christ as a preacher of the Gospel are contrasted with one another, we believe, teach, and confess that the Gospel is not a preaching of repentance or reproof, but properly nothing else than a preaching of consolation, and a joyful message which does not reprove or terrify, but comforts consciences against the terrors of the Law, points alone to the merit of Christ, and raises them up again by the lovely preaching of the grace and favor of God, obtained through Christ’s merit.
8] 7. As to the revelation of sin, because the veil of Moses hangs before the eyes of all men as long as they hear the bare preaching of the Law, and nothing concerning Christ, and therefore do not learn from the Law to perceive their sins aright, but either become presumptuous hypocrites [who swell with the opinion of their own righteousness] as the Pharisees, or despair like Judas, Christ takes the Law into His hands, and explains it spiritually, Matt. 5:21ff ; Rom. 7:14. And thus the wrath of God is revealed from heaven against all sinners [ Rom. 1:18 ], how great it is; by this means they are directed [sent back] to the Law, and then first learn from it to know aright their sins-a knowledge which Moses never could have forced out of them.
9] Accordingly, although the preaching of the suffering and death of Christ, the Son of God, is an earnest and terrible proclamation and declaration of God’s wrath, whereby men are first led into the Law aright, after the veil of Moses has been removed from them, so that they first know aright how great things God in His Law requires of us, none of which we can observe, and therefore are to seek all our righteousness in Christ:
10] 8. Yet as long as all this (namely, Christ’s suffering and death) proclaims God’s wrath and terrifies man, it is still not properly the preaching of the Gospel, but the preaching of Moses and the Law, and therefore a foreign work of Christ, by which He arrives at His proper office, that is, to preach grace, console, and quicken, which is properly the preaching of the Gospel.
Negative Theses: Contrary Doctrine which is Rejected.
11] Accordingly we reject and regard as incorrect and injurious the dogma that the Gospel is properly a preaching of repentance or reproof, and not alone a preaching of grace; for thereby the Gospel is again converted into a doctrine of the Law, the merit of Christ and Holy Scripture are obscured, Christians robbed of true consolation, and the door is opened again to [the errors and superstitions of] the Papacy.
The texts used here are from Triglot Concordia: The Symbolical Books of the Evangelical Lutheran Church: German-Latin-English. Published as a memorial of the quadricentenary jubilee of the Reformation anno Domini 1917 by resolution of the Evangelical Lutheran Synod of Missouri, Ohio, and Other States (St. Louis: Concordia Publishing House, 1921). These texts are in the public domain and may be freely copied.