Yes God made the Covenant forever...but the Jews broke it. Like any contract. If one party breaks the contract, the other party has no contract. God being a loving God, had his son offer a new contract to all people, and the Jews who broke the old contract, also rejected the new contract. Any Jew can be a part of the new Covenant. The tribe of Judah as a whole can not.
A promise is a promise and God promises that he would never leave the Covenant. Secondly, when you say "Jews broke it", that is a stereotype. Instead of abandoning us, God says in Ezekiel and other verses in the Tanakh that we will be judged as
individuals. Also, just a reminder that the Covenant was given
before the Law, so adherence to the Covenant is not based on obeying the Law itself.
Anyhow, just a few verses for you to consider:
Genesis 17:[7] And I will establish my covenant between me and you and your descendants after you throughout their generations for an everlasting covenant, to be God to you and to your descendants after you.
Genesis 17:[13] both he that is born in your house and he that is bought with your money, shall be circumcised. So shall my covenant be in your flesh an everlasting covenant.
Deuteronomy 7:[9] Know therefore that the LORD your God is God, the faithful God who keeps covenant and steadfast love with those who love him and keep his commandments, to a thousand generations,
Deuteronomy 29:[12] that you may enter into the sworn covenant of the LORD your God, which the LORD your God makes with you this day;
[13] that he may establish you this day as his people, and that he may be your God, as he promised you, and as he swore to your fathers, to Abraham, to Isaac, and to Jacob.
Psalms 89:[34] I will not violate my covenant,
or alter the word that went forth from my lips.
Psalms 105:[8] He is mindful of his covenant for ever,
of the word that he commanded, for a thousand generations,
Isaiah 44:[21] Remember these things, O Jacob,
and Israel, for you are my servant;
I formed you, you are my servant;
O Israel, you will not be forgotten by me.
Isaiah 45:[17] But Israel is saved by the LORD
with everlasting salvation;
you shall not be put to shame or confounded
to all eternity.
Isaiah 52:[1] Awake, awake,
put on your strength, O Zion;
put on your beautiful garments,
O Jerusalem, the holy city;
for there shall no more come into you
the uncircumcised and the unclean.
Isaiah 59:[20] "And he will come to Zion as Redeemer,
to those in Jacob who turn from transgression, says the LORD.
[21] "And as for me, this is my covenant with them, says the LORD: my spirit which is upon you, and my words which I have put in your mouth, shall not depart out of your mouth, or out of the mouth of your children, or out of the mouth of your children's children, says the LORD, from this time forth and for evermore."
Isaiah 66:[22] "For as the new heavens and the new earth
which I will make
shall remain before me, says the LORD;
so shall your descendants and your name remain.
