25 For I do not want you to be ignorant of this mystery, brothers and sisters, so that you may not be conceited: A partial hardening has happened to Israel until the full number of the Gentiles has come in. 26 And so all Israel will be saved, as it is written:“The Deliverer will come out of Zion; he will remove ungodliness from Jacob. 27 And this is my covenant with them, when I take away their sins.” 28 In regard to the gospel they are enemies for your sake, but in regard to election they are dearly loved for the sake of the fathers. 29 For the gifts and the call of God are irrevocable.
Kiddushin 36aBabylonian Talmud
And Rabbi Meir says: Either way you are still called sons, as it is stated: “They are foolish sons” (Jeremiah 4:22). And it also states: “Sons in whom there is no faithfulness” (Deuteronomy 32:20). And it states: “A seed of evildoers, sons who deal corruptly” (Isaiah 1:4). And it states: “And it shall come to pass that, instead of what was said to them: You are not My people, it shall be said to them: Sons of the living God” (Hosea 2:1). The Gemara asks: Why is it necessary to cite these additional proofs introduced by the phrase: And it states? All these verses apparently make the same point. The Gemara explains why all the quotes are necessary. And if you would say: Granted, when they are foolish they are still called sons, as the verse states: “Foolish sons,” but when they do not have faithfulness they are not called sons; therefore, come and hear another verse. And that verse states: “Sons in whom there is no faithfulness.”
Notes and References
"... In spite of what might initially seem to be the meaning of the 'on condition that' passages — that God would cancel the covenant if its conditions were not fulfilled — there is actually no hint of such a view in the entire body of Tannaitic literature. The 'on condition that' passages themselves are not directed toward such a possibility. Partially, they are hortatory, insisting that the named commandment should be observed. The primary intention, however, is to emphasize that anyone wishing to deny the implications of the covenant — the obligation to keep its commandments — is considered to be rejecting the covenant itself, essentially 'denying the exodus.' While such a person may choose to withdraw from the covenant, this does not imply cancellation on God's part. The Rabbis never doubted that God would remain faithful to the covenantal promises, even when met with disobedience. This universal view is distinctly stated by R. Jose (b. Halafta): 'No word of blessing that issued from the mouth of the Holy One, blessed be He, even if based upon a condition, was ever withdrawn by Him.' This point is elaborated in the Mekilta, where R. Eleazar b. R. Jose says in the name of Abba Jose the son of the Damascene: "And God saw the children of Israel," knowing that they would provoke Him in the future; 'and God took cognizance of them,' knowing that they would blaspheme in the future. So why was He so lenient? Because of the power of repentance. Similarly, why does it say that "He was their Savior" (Isaiah 63.8) when He knew that Israel would deal falsely with Him? Because 'He, being full of compassion, forgives iniquity' (Psalm 78:38). The only possible exception to this view — that God maintained the promises of the covenant despite disobedience — is a remark attributed to R. Judah (Sifre Deuteronomy 96 (157; to 14.1); compare Kiddushin 36a) ..."
Sanders, E. P. Paul and Palestinian Judaism: A Comparison of Patterns of Religion (p. 95) Fortress Press, 1977