It is the fashion now to place the Sermon on the Mount in contrast with the rest of the New Testament. “We will have nothing to do with theology,” men say in effect, “we will have nothing to do with miracles, with atonement, or with heaven or with hell. For us the Golden Rule is a sufficient guide of life; in the simple principles of the Sermon on the Mount we discover a solution of all the problems of society.” It is indeed rather strange that men can speak in this way. Certainly it is rather derogatory to Jesus to assert that never except in one brief part of His recorded words did He say anything that is worth while.
But even in the Sermon on the Mount there is far more than some men suppose. Men say that it contains no theology; in reality it contains theology of the most stupendous kind. In particular, it contains the loftiest possible presentation of Jesus’ own Person. That presentation appears in the strange note of authority which pervades the whole discourse; it appears in the recurrent words, “But I say unto you.” Jesus plainly puts His own words on an equality with what He certainly regarded as the divine words of Scripture; He claimed the right to legislate for the Kingdom of God. Let it not be objected that this note of authority involves merely a prophetic consciousness in Jesus, a mere right to speak in God’s name as God’s Spirit might lead. For what prophet ever spoke in this way? The prophets said, “Thus saith the Lord,” but Jesus said, “I say.” We have no mere prophet here, no mere humble exponent of the will of God; but a stupendous Person speaking in a manner which for any other person would be abominable and absurd.
The same thing appears in the passage Matt. 7:21-23: “Not everyone who says to me Lord, Lord, shall enter into the Kingdom of Heaven, but he who does the will of my Father who is in heaven. Many shall say to me in that day: Lord, Lord, have we not prophesied in thy name, and in thy name cast out demons, and in thy name done many mighty works? And then I shall confess to them, ‘I never knew you; depart from me, ye that work lawlessness.'” This passage is in some respects a favorite with modern liberal teachers; for it is interpreted–falsely, it is true, yet plausibly–as meaning that all that a man needs to attain standing with God is an approximately right performance of his duties to his fellowmen, and not any assent to a creed or even any direct relation to Jesus. But have those who quote the passage 80 triumphantly in this way ever stopped to reflect upon the other side of the picture–upon the stupendous fact that in this same passage the eternal destinies of men are made dependent upon the word of Jesus ? Jesus here represents Himself as seated on the judgment-seat of all the earth, separating whom He will forever from the bliss that is involved in being present with Him. Could anything be further removed than such a Jesus from the humble teacher of righteousness appealed to by modern liberalism? Clearly it is impossible to escape from theology, even in the chosen precincts of the Sermon on the Mount. A stupendous theology, with Jesus’ own Person at the center of it, is the presupposition of the whole teaching.
Adapted from J. Gresham Machen, Christianity and Liberalism (Kindle Edition)