It is a mistake to take the words of Jesus, the Christ of God, as being somehow more inspired than what others spoke and recorded in the Scriptures. Paul, and Jesus, shared the same Holy Spirit, and uttered exactly what God wanted to have known. Holy Spirit is not subject to men, but inspires them to write His own words.
The New Covenant is Jewish, and is the fulfillment of Jeremiah 31. The Lord sealed that covenant with His people while on earth. It is not for the Gentile nations, and does not include us.
Jer 31:33 For this [is] the covenant that I make, With the house of Israel, after those days, An affirmation of Yahweh, I have given My law in their inward part, And on their heart I do write it, And I have been to them for Elohim, And they are to me for a people.
The house of Israel, after those days, which have not come yet. It is prophetic, future, and yet to obtain.
In every way I agree that the so-called New Testament is Hebrew in scope, and a continuation of God’s dealings with His people. But the Apostle Paul was not commissioned for the Jews only, his ministry was for the Gentile nations, apart from Israel and during this era of their Stubbornness. Remove all of Paul’s letters and the Scriptures become wholly Hebrew from front to back, and mention nothing of the Gentiles other than their subservient place in the plan of God.
The words that Jesus spoke are truth and life, yet, if you believe God, then Paul’s words are no less important and true.
Jesus is Lord, and Paul is His slave.
“Behold, the days are coming, declares the Lord, when I will establish a new covenant with the house of Israel and with the house of Judah,
9 not like the covenant that I made with their fathers on the day when I took them by the hand to bring them out of the land of Egypt. For they did not continue in my covenant, and so I showed no concern for them, declares the Lord.
10 For this is the covenant that I will make with the house of Israel after those days, declares the Lord: I will put my laws into their minds, and write them on their hearts,and I will be their God, and they shall be my people.
11 And they shall not teach, each one his neighbor and each one his brother, saying, ‘Know the Lord, for they shall all know me, from the least of them to the greatest.
First of all, the covenant is NOT made with gentiles, it is made with the house of Israel(Ephraim) & the house of Judah & NO ONE else.
Second, when this covenant is fulfilled, ALL Israel, both the house of Israel(Ephraim) & the house of Judah know their Messiah, ALL of them. THIS HAS NOT YET HAPPENED!
And third, the writer specifically says the new covenant that is made with the children of those whom were brought out of Egypt, it is the location of the covenant that has changed, not the terms of the covenant. It is written on hearts, never again to be written in stone. The Law of God once written on stone, now written on our hearts that we may know it & have the heart of the Word of God in us to do it. You know, "I can do all through Him who is in me"? Well, who is that Him in us, He is the living Word of God of Israel writing His Law upon our hearts that we may become imitators of Him as Paul imitated Him. (Eph 5:1, 1Cor 11:1) As Jesus said, He did nothing except what He saw His Father doing, and thus when we imitate Christ as Paul imitated Christ, then we too are imitating & pleasing our Father in Heaven.(Rm 8)
Shalom