It may seem strange to hear someone say that ministers need to learn how to preach Christ from the Gospels; but in light of the failure, in this regard, of so many when dealing with the commands of Christ (case in point), there is perhaps no greater need for minsters of the Gospel at present than to learn this principle and etch it into their minds and hearts. I had a friend in seminary who once said to me, “We don’t need to preach the cross when we are preaching through the Sermon on the Mount, because Jesus didn’t.” Thankfully my friend has forgotten saying this (and has subsequently changed his mind!), but the reality is that many Evangelical and Reformed ministers approach a particular text in the Gospels in an atomistic way. They read any given passage as separated from the central teaching of the atoning death of Christ. They detach the ethical teachings of Jesus from the story of Jesus. As we read the Gospel records we must always remember that the One who preached the Sermon on the Mount is the very One who had “set His face steadfastly to go to Jerusalem” to die on the cross for the salvation of His people. If there is one thing that the evil one wants us to forget, it is the message of the cross.
Geerhardus Vos, in his sermon Hungering and Thirsting After Righteousness, gave the much needed principle when he came to explain that all the teaching of the Sermon on the Mount must be understood in the light of the saving work of the Christ–the One preaching the sermon. Since so many have mistakenly reduce Christianity to the set of ethical principles taught in the Sermon on the Mount–as detached from the message of the grace of God in the Gospel–Vos noted:
It is not so much what people find in the Sermon on the Mount, it is what they congratulate themselves for not finding there, that renders them thus enamored of its excellence. It is because they dislike the story of the helplessness of man, of man’s utter condemnation in the sight of God, and the insistence upon the necessity of the cross…All such forget that both Jesus and the Evangelists expressly relate the Sermon on the Mount to the disciples, and consequently place back of what is described in it the process of becoming a disciple, the whole rich relationship of saving approach and responsive faith, of calling and repentance and pardon and acceptance and the following of Jesus, all that makes the men and women of the Gospels such disciples and Jesus such a Lord and Savior as this and other records of His teaching imply. It is therefore folly to suggest that no specific doctrine of salvation is here. It is present as a living doctrine in the Person of Jesus. We are apt to forget that in the days of our Lord’s flesh there was no need for the explicit teaching about the Christ found in the Epistles of the New Testament. At that time He, the real Christ, walked among men and exhibited in His intercourse with sinners, more impressively than any abstract doctrine could have done, the principles and the process of salvation. If we have but eyes to see, we shall find our Savior in the out-door scenes of the Gospels, no less than in the walls of the school of the Epistle to the Romans. And we shall find Him too in the Sermon on the Mount. For this discourse throughout presupposes that the disciples, here instructed, became associated with Jesus as sinner needing salvation, and that their whole life in continuance is lived on the basis of grace. (pp. 39-40)
Sinclair Ferguson, in his sermon The Waiting Father, puts this principle to work in the most masterful way. Explaining the joy with which the Father received the younger son, Ferguson explained:
All of this loss has been sustained in the heart of the Father. This is why the joy is so great in the heart of the Father because the loss has been felt so keenly. Now why is that so significant in this story? For one reason, because in this story there are actually three sons: there’s the younger son who leaves home; there’s the older son who stayed at home; and there’s the eternal Son whose telling the story. And the story of that eternal Son is that in some time He is going to be given up to the cross, and He is going to cry out “My God, My God, Why have you forsaken Me?” in a sense that He has lost His Father; and there is going to be an echoing cry in the heart of the Heavenly Father, much deeper than the cry of King David in the death of his son Absalom, “Oh Absalom, my son, Absalom, my son, my son Absalom.” And you see its the story that’s taking place outside of the story of Luke 15, that makes the story in Luke 15 both possible and glorious. You remember how Paul sumamarizes this in what seems to me to be one of the greatest utterances in all of history, “The God who did not spare His own Son, but gave Him up for us all, how will He not also with Him freely give us all things.”
This raises one final question. Why do the apostles speak more clearly and pervasively about the significance of the death and resurrection of Jesus, than the Lord did in the days of His flesh? In seeking to answer this question Vos suggested that, “the relation between Jesus and the Apostolate is in general that between the fact to be interpreted and the subsequent interpretation of the fact.” In other words, the Gospels are the historical narrative of all that Jesus did and taught. The epistles are the inspired commentaries on the Gospels, in which the Apostles interpret the facts of Jesus for the New Covenant church.