Law and gospel must also be understood as the basic homiletical device in the church. The sermon must reflect the tension created by the God who condemns and redeems the Christian at the same time. The hearer must never be allowed to fall back on the laurels of his own morality or spiritual accomplishments. The listener is pummeled continuously by the law and the gospel. Testimonies of spiritual greatness must be replaced by the proclamation of God’s fulfilling of his own law in Christ and the freedom which is now given the Christian in Christ. The law and the gospel should be seen as the key to man’s existential self-dilemma in understanding himself and his relationship to God. If the universal atonement means anything, it means that God had satisfied all of the law’s requirements, its demands and penalties, in the person of God’s Son, Jesus Christ. The law no longer can describe how God views man. The gospel can never be nullified. The gospel is never conditional, since incarnation and atonement are permanent realities with God. Our moral and spiritual failures do not trigger a negative response in God so that he returns to the old covenant. The former agenda of penalty is not reinstated. This has been satisfied once and for all. For what reason is anyone now condemned, if the law is not in effect? A great condemnation awaits those who reject God’s free gift in Christ. Under the covenant of the law, we failed to do what God required. Those who reject the gospel have not failed to fulfill a requirement, that would make the gospel only another law, they have rejected what God has freely done. Sinners are accepted by Christ. Those who reject him are not.
Two sayings are attributed to Luther. He promised a doctor’s cap to any one who could rightly distinguish between the law and the gospel. Even theologians who can dogmatically distinguish between them cannot preach it. The other has to do with good works. The Christian does not need the motivation of the law simply because he is so busy doing good works. Still the motivation of the law is there, but not law as demand, punishment, and reward, but law as fulfilled in Christ. In spite of the terrible spiritual agony Luther experienced as long as he lived, he was not a dour, gloomy or sullen person, as some other reformers were reputed to be. Quite to the contrary he never overcame some of his crude peasant speech, which today would be looked upon by some as signs of an unsanctified life. When faced with his own greatness, he said that God brought about the Reformation while he and Melanchthon drank beer. He was annoyed with Melanchthon’s obsession with minor sins and urged him to do something really sinful: “sin boldly.” As a hymn writer, where the brine of the middle ages merged with the sweet waters of the Reformation, Luther was unmatched. He spoke about the Christian merrily going about his business and doing good. The law and the gospel is the secret to understanding Luther. No longer is my chief concern restraining from moral evil and then coming to the conclusion that I have lived a sanctified life and thus triumphed. Christians are never free from sin, but they are so busy doing good, that even when they fall into sin as they do good, this is all covered by grace.
David P. Scaer, “The Law and the Gospel in Lutheran Theology“