You keep making this false claims, without any support.
The new covenant is between the same parties as the old. That is what the Bible says, but you disagree. That's your problem.
Jer 31:31-34 (AKJV/PCE)
(31:31) ¶ Behold, the days come, saith the LORD, that I will make a new covenant with the house of Israel, and with the house of Judah: (31:32) Not according to the covenant that I made with their fathers in the day [that] I took them by the hand to bring them out of the land of Egypt; which my covenant they brake, although I was an husband unto them, saith the LORD: (31:33) But this [shall be] the covenant that I will make with the house of Israel; After those days, saith the LORD, I will put my law in their inward parts, and write it in their hearts; and will be their God, and they shall be my people. (31:34) And they shall teach no more every man his neighbour, and every man his brother, saying, Know the LORD: for they shall all know me, from the least of them unto the greatest of them, saith the LORD: for I will forgive their iniquity, and I will remember their sin no more.
Just read it and believe it. It's just crystal clear.
P.S. Note that "with their fathers" makes it completely clear WHO the LORD is talking about!
Looks like Barnabas does not agree with your assessment.
Epistle of Barnabas
CHAPTER 4
Warning that the final trial is at hand -- The covenant. Christian or Jewish? -- Admonition to stedfastness
1 We ought, then, to enquire earnestly into the things which now are, and to seek out those which are able to save us. Let us then utterly flee from all the works of lawlessness, lest the works of lawlessness overcome us, and let us hate the error of this present time, that we may be loved in that which is to come.
2 Let us give no freedom to our souls to have power to walk with sinners and wicked men, lest we be made like to them.
3 The final stumbling block is at hand of which it was written, as Enoch says, "For to this end the Lord has cut short the times and the days, that his beloved should make haste and come to his inheritance."
4 And the Prophet also says thus: "Ten kingdoms shall reign upon the earth and there shall rise up after them a little king, who shall subdue three of the kings under one."
5 Daniel says likewise concerning the same: "And I beheld the fourth Beast, wicked and powerful and fiercer than all the beasts of the sea, and that ten horns sprang from it, and out of them a little excrescent horn, and that it subdued under one three of the great horns."
6
You ought then to understand. And this also I ask you, as being one of yourselves, and especially as loving you all above my own life; take heed to yourselves now,
and be not made like unto some, heaping up your sins and saying that the covenant is both theirs and ours.
7
It is ours: but in this way did they finally lose it when Moses had just received it, for the Scripture says: "And Moses was in the mount fasting forty days and forty nights, and he received the covenant from the Lord, tables of stone written with the finger of the hand of the Lord."
8 But they turned to idols and lost it. For thus saith the Lord: "Moses, Moses, go down quickly, for thy people, whom thou broughtest forth out of the land of Egypt, have broken the Law." And Moses understood and cast the two tables out of his hands,
and their covenant was broken, in order that the covenant of Jesus the Beloved should be sealed in our hearts in hope of his faith.
9
(And though I wish to write much, I hasten to write in devotion to you, not as a teacher, but as it becomes one who loves to leave out nothing of that which we have.) Wherefore let us pay heed in the last days, for the whole time of our life and faith will profit us nothing, unless we resist, as becomes the sons of God in this present evil time, against the offences which are to come, that the Black One may have no opportunity of entry.
10 Let us flee from all vanity, let us utterly hate the deeds of the path of wickedness. Do not by retiring apart live alone as if you were already made righteous, but come together and seek out the common good.
11 For the Scripture says: "Woe to them who are prudent for themselves and understanding in their own sight." Let us be spiritual, let us be a temple consecrated to God, so far as in us lies let us "exercise ourselves in the fear" of God, and let us strive to keep his commandments in order that we may rejoice in his ordinances.
12 The Lord will "judge" the world "without respect of persons." Each will receive according to his deeds. If he be good his righteousness will lead him; if he be evil the reward of iniquity is before him.
13 Let us never rest as though we were `called' and slumber in our sins, lest the wicked ruler gain power over us and thrust us out from the Kingdom of the Lord.
14 And consider this also, my brethren, when you see that after such great signs and wonders were wrought in Israel they were even then finally abandoned; -- let us take heed lest as it was written we be found "many called but few chosen."