This does not prove that God has failed to do for Abraham what he promised, because, as Scripture illustrates, it is not all who are naturally descended from Jacob or Abraham whom God considers to be his children, but it is those who were born as a result of what God promised whom he considers his children.

Romans 9:6-13

6 God promised to Abraham, Isaac, and Jacob, that their descendants would all inherit his blessings. But although most of my fellow Israelites have rejected Christ, that does not prove that God has failed to do the things that he promised, because it is not all who are descended from Jacob and who call themselves the people of Israel whom God considers to be truly his people. 7 And it is also not all of Abraham’s natural descendants that God considers to be his people. Instead, God considers only some of them to be Abraham’s children. This agrees with what God told Abraham: “It is Isaac, not any of your(sg) other sons, whom I will consider to be the true father of your descendants.” 8 That means that it is not all the natural-born descendants of Abraham whom God considers as his children. Instead, it is those who believed what God promised whom he considers to be his children. 9 You know that what God promised to Abraham was this: “About this time next year Sarah your wife will bear a son as a result of my enabling [MTY] her to do so.” So Abraham knew that it was not through Ishmael, the son that he already had, that God would fulfill what he had promised him (OR, that his true descendants would come). 10 And not only then did God show that he did not determine who would be his true children according to who their ancestors were. He showed it again when Rebecca conceived twins by our ancestor Isaac. 11-12 11-12Before the twins, Jacob and Esau, were born, when neither one had yet done anything good or bad, God said to Rebecca about the twins she was to bear, “The older one shall later serve the younger one, contrary to normal custom.” God said this in order that we might clearly understand that what he purposed for people was according to what he himself determined. That is, people’s eternal destiny does not depend on what they do. Instead, their destiny depends on God, the one who chooses them. 13 And this teaching is ◄supported/shown to be true► by what is written in the Scriptures {what a prophet recorded} that God said: “I favored Jacob, the younger son. I did not favor [HYP] Esau, the older son.”