We have now come to Lecture 6 and
Rightly distinguishing the Law and the Gospel is the most difficult and the highest art of Christians in general and of theologians in particular. It is taught only by the Holy Spirit in the school of experience.
Possibly some one among you is thinking, “Is this thesis really true? I have now heard five lectures on this subject, and it is perfectly clear to me. If this is the most difficult art, I know it.” But, my dear friend, you are greatly mistaken. Consider that the thesis does not mean that the doctrine of the Law and the Gospel is so difficult that it cannot be learned without the aid of the Holy Ghost. It is easy — easy enough for children to learn. Every child can comprehend this doctrine. It is contained in every catechism. It is not strong meat, but milk. It is the first letters of the alphabet, it belongs to the rudiments of Christianity; for without this doctrine no person can be a Christian. Even a small child soon learns these facts: “The First Part of the Catechism treats of the Tent Commandments, the Second Part of the Creed. We are first told what we are to do; next, that a person need only believe to be saved.” In other words, the child observes that the Second Part does not, like the First, make demands. This doctrine of the distinction of Law and Gospel is entirely different from the doctrine of the attributes by which the three persons in the Godhead are distinct from one another; or the doctrine of predestination with its many inscrutable mysteries, or the doctrine of the communication of the divine attributes to the human nature of Christ. These doctrines exceed the grasp of children and cannot be comprehended by them. But the doctrine of the distinction between the Law and the Gospel is different. You know it now. But at the present time we are studying the application and the use of this doctrine. The practical application of this doctrine presents difficulties which no man can surmount by reasonable reflections. The Holy Spirit must teach men this in the school of experience.
…Luke 5, 8 we have the cry of Peter: Depart from me, for I am a sinful man, O Lord. Is not this a remarkable incident? The Lord comes to the disciples whom He had named Petros, a rock-man, and bids him and his fellow-fishermen, after an unsuccessful night on the lake, to drop their nets in deep water. Peter complied, most likely expecting, however, that he would catch nothing. But, lo! they caught such a multitude of fishes that their nets broke. Now Peter is seized with fear. He reflects: “That must be the almighty God Himself who has spoken to me That must be my Maker. He will one day be my Judge!” He falls down at Jesus’ knees and says: “Depart from me, for I am a sinful man, O Lord.” He expects the Lord to say to him: “Look at the multitude of sins thou hast committed. Thou art worthy of everlasting death and damnation.” Whence, then, came Peter’s fright? Why did he not thank Jesus when he fell down at His knees? Because his many sins passed before his mind’s eye, and in that condition it was impossible for him to express cheerful gratitude, but had to drop trembling to his knees and cry to his Lord and Savior those awful words: “Depart from me, O Lord.” The devil had robbed him of all comfort and whispered to him that he must speaks thus to Jesus. He expected nothing else than to be slain by the Lord. He was incapable of distinguishing Law and Gospel. If he had been able to do this, he could have approached Jesus cheerfully, remembering that He had forgiven all his sins. Many a time in his later life he probably said to himself: “Peter, you were a great simpleton on that occasion. Instead of what you did say to Jesus, you should have said: O Lord, abide with me, for I am a sinful man.” That is what he did on a later occasion when he had fallen into another sin. Then he was filled with joy unspeakable when Jesus gave him that look full of gracious compassion.