“Now to strengthen this faith, God has promised this gospel and testament in many ways, by the prophets in the Old Testament, as St. Paul says in Romans 1[:1], 'I am set apart to preach the gospel of God which he promised beforehand through his prophets in the holy scriptures, concerning his Son, who was descended from David,' etc.
    “To mention some of these places: God gave the first promise when he said to the serpent, in Genesis 3[:15], 'I will put enmity between you and the woman, and between your seed and her seed; he shall bruise your head, and you shall bruise his heel.' Christ is this woman’s seed, who has bruised the devil’s head, that is, sin, death, hell, and all his power. For without this seed, no man can escape sin, death, or hell.
    “Again, in Genesis 22[:18], God promised Abraham, 'Through your descendant shall all the nations of the earth be blessed.' Christ is that descendant of Abraham, says St. Paul in Galatians 3[:16]; he has blessed all the world, through the gospel [Gal. 3:8]. For where Christ is not, there is still the curse that fell upon Adam and his children when he had sinned, so that they all are necessarily guilty and subject to sin, death, and hell. Over against this curse, the gospel now blesses all the world by publicly announcing, 'Whoever believes in this descendant of Abraham shall be blessed.' That is, he shall be rid of sin, death, and hell, and shall remain righteous, alive, and saved forever, as Christ himself says in John 11[:26], 'Whoever believes in me shall never die.'
    “Again God made this promise to David in II Samuel 7[:12–14] when he said, 'I will raise up your son after you, who shall build a house for my name, and I will establish the throne of his kingdom forever. I will be his father, and he shall be my son,' etc. This is the kingdom of Christ, of which the gospel speaks: an everlasting kingdom, a kingdom of life, salvation, and righteousness, where all those who believe enter in from out of the prison of sin and death.
    “There are many more such promises of the gospel in the other prophets as well, for example Micah 5[:2], 'But you, O Bethlehem Ephrathah, who are little to be among the clans of Judah, from you shall come forth for me one who is to be ruler in Israel'; and again, Hosea 13[:14], 'I shall ransom them from the power of hell and redeem them from death. O death, I will be your plague; O hell, I will be your destruction.'
    “The gospel, then, is nothing but the preaching about Christ, Son of God and of David, true God and man, who by his death and resurrection has overcome for us the sin, death, and hell of all men who believe in him. Thus the gospel can be either a brief or a lengthy message; one person can write of it briefly, another at length. He writes of it at length, who writes about many words and works of Christ, as do the four evangelists. He writes of it briefly, however, who does not tell of Christ’s works, but indicates briefly how by his death and resurrection he has overcome sin, death, and hell for those who believe in him, as do St. Peter and St. Paul.”  Martin Luther, Luther’s Works, Vol. 35, Page 359-360.