We have finished Thesis I, and lecture 2, but Walther protests “Even to-night we cannot take leave of our thesis at once.” Most of Lecture 3 consists of extensive Luther quotes “from Luther’s exposition of chapters 6, 7, and 8 of the Gospel of St. John, written in the years 1530 to 1532,” but Walther’s introduction is great in its own right:
Christ Himself has described the way to heaven as a narrow path. Just so narrow is the path of the pure doctrine. For the pure doctrine is nothing else than the doctrine regarding the way to heaven. It is easy to lose your way when it is narrow, rarely traveled, and leads through a dense forest. Without intending to do so and without being aware of it, you may make a wrong turn to the right or left. It is equally easy to lose the narrow way of the pure doctrine which likewise is traveled by few people and leads through a dense forest of erroneous teachings. You may land either in the bog of fanaticism or in the abyss of rationalism. This is no jest. False doctrine is poison to the soul. An entire banqueting party drinking from cups containing an admixture of arsenic can drink physical death from its cups. So an entire audience can invite spiritual and eternal death by listening to a sermon that contains an admixture of the poison of false doctrine. A person can be deprived of his soul’s salvation by a single false comfort or a single false reproof administered to him. This is all the more easy because we are all naturally more accessible to the shining and dazzling light of human reason than to the divine truth. For “the natural man receiveth not the things of the Spirit of God, for they are foolishness unto him; neither can he know them.” 1 Cor. 2, 14.
From what has been said you can gather how foolish it is, yea, what an awful delusion has taken hold upon so many men’s minds who ridicule the pure doctrine and say to us: “Ah, do cease clamoring, Pure doctrine! Pure doctrine! That can only land you in dead orthodoxism. Pay more attention to pure life, and you will raise a growth of genuine Christianity.” That is exactly like saying to a farmer: “Do not worry forever about good seed; worry about good fruits.” Is not a farmer properly concerned about good fruit when he is solicitous about getting good seed? Just so a concern about pure doctrine is the proper concern about genuine Christianity and a sincere Christian life. False doctrine is noxious seed, sown by the enemy to produce a progeny of wickedness. The pure doctrine is wheat-seed; from it spring the children of the Kingdom, who even in the present life belong in the kingdom of Jesus Christ and in the life to come will be received into the Kingdom of Glory. May God even now implant in your hearts a great fear, yea, a real abhorrence, of false doctrine! May He graciously give you a holy desire for the pure, saving truth, revealed by God Himself! That is the chief end which these evening lectures are to serve.
The extensive Luther quotes are good as well, of course (by all means, go read them!), but I will pass over all but this bit of commentary:
Of course, you cannot speak like Luther. Still you must revolve in your mind this problem: “How can I preach the Law to the secure and the Gospel to crushed sinners?” Every sermon must contain both doctrines. When either is missing, the other is wrong. For any sermon is wrong that does not present all that is necessary to a person’s salvation. You must not think that you have rightly divided the Word of Truth if you preach the Law in one part of your sermon and the Gospel in the other. No; a topographical division of this kind is worthless. Both doctrines may be contained in one sentence. But in your audience every one must get the impression, “That is meant for me.”