Back in the day, liberal theologians liked to say Jesus never claimed any particularly extraordinary authority for himself; not to be the Messiah, the Son of God, or any of it, and that all of the church’s later teaching on it was an unjustified addition and corruption of Jesus’ originally pure, moral message about God’s Fatherhood, and the universal brotherhood of man. Usually this claim was advanced in order to forward a less doctrinally-”rigid” Christianity, more in keeping with the modern spirit, picturing Jesus as a teacher of universal moral truths and general wisdom suited to their post-Victorian sensibilities.
Actually, this kind of move still gets made today only we don’t use the “sexist” and gendered language of the “Fatherhood of God”, or the “brotherhood of man.” Typically we replace that with some talk about justice, equality, the end of oppression and such things. Now, don’t get me wrong, justice and ending oppression are good, biblical things. Still, it’s not uncommon to hear sentiments like, ”If only we could forget all this business about Christ being ‘Lord’, or those abstruse Trinitarian controversies, or his atoning death with all of the silly theological disputes that go along with it, we could get down to the real business Jesus was about–you know, all that stuff in the Sermon on the Mount. The Sermon on the Mount! That’s the real Jesus. That’s the Jesus we should be listening to, considering, and putting what he preaches into practice. The Sermon on the Mount is where you find what Jesus was really all about–not all of this silly dogma about him that mainstream Christianity has gotten hi-jacked with.”
Basically, if we could get Jesus’ ethics, his moral teachings, without all the doctrine, then we’d be good. When J. Gresham Machen encountered this line of thinking back in his own day he pointed out the flaw, at least from the New Testament standpoint, with it:
Even those parts of the Gospels which have been regarded as most purely ethical are found to be based altogether upon Jesus’ lofty claims….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. -Christianity and Liberalism, pg. 31-32
In essence he said, “Fine, let’s look at the Sermon on the Mount. Let’s see what kind of Jesus we find there: the Jesus who quotes himself.” What’s significant about that? Well, I mean, even in our modern context if you find a guy walking around quoting himself, you know he’s got a high opinion of himself. In the Bible this was a slightly bigger deal. See, a prophet of God would say, “Thus says the Lord”, but Jesus goes ahead and basically says, “Here’s what I say”–essentially elevating his word alongside the word of Lord. Actually, Machen goes on to point out that Jesus explicitly does that:
The same thing appears in the passage Matt. vii. 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 fellow-men, and not any assent to a creed or even any direct relation to Jesus. But have those who quote the passage 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. -ibid., pg 32
Basically, if you want the Jesus of the Sermon on the Mount, you can’t get away from that Jesus of “doctrine”. Inevitably Jesus himself points you to the Jesus of the creeds–the Messiah, dead, buried, risen, ascended, the ruling and reigning Lord, equal with the Father, and coming to judge the quick and the dead. There is no ethical Jesus without the doctrinal Jesus; eventually you have to deal with the Jesus who quotes himself.
Soli Deo Gloria