'Descendants' in the Bible

For the promise to Abraham or to his descendants that he would inherit the world was not through the law, but through the righteousness that comes by faith.

This is why the promise is by faith, so that it may be according to grace, to guarantee it to all the descendants—not only to those who are of the law but also to those who are of Abraham’s faith. He is the father of us all

so that the promise should be made sure to all Abraham's true descendants; not merely to those who are righteous through the Law, but to those who are righteous through a faith like that of Abraham. Thus in the sight of God in whom he believed, who gives life to the dead and makes reference to things that do not exist, as though they did, Abraham is the forefather of all of us. As it is written, "I have appointed you to be the forefather of many nations."

He believed, hoping against hope, so that he became the father of many nations according to what had been spoken: So will your descendants be.

Neither are they all children because they are Abraham’s descendants. On the contrary, your offspring will be traced through Isaac.

That is, it is not merely the children born through natural descent who were regarded as God's children, but it is the children born through the promise who were regarded as descendants.

Isaiah also calls out concerning Israel, "Although the descendants of Israel are as numerous as the grains of sand on the seashore, only a few will be saved.

It is just as Isaiah predicted: "If the Lord of the Heavenly Armies had not left us some descendants, we would have become like Sodom and would have been compared to Gomorrah."

while the descendants of Israel, who were in pursuit of a Law that could give righteousness, have not arrived at one.

Therefore I say, God has not rejected his people, has he? May it never be! For I also am an Israelite, from the descendants of Abraham, of the tribe of Benjamin.

I ask, however, "Have they stumbled so as to be finally ruined?" No, indeed; but by their lapse salvation has come to the Gentiles in order to arouse the jealousy of the descendants of Israel;