'Descendants' in the Bible

For the promise to Abraham or to his descendants that he would be heir of the world was not through the Law, but through the righteousness of faith.

For this reason it is by faith, in order that it may be in accordance with grace, so that the promise will be guaranteed to all the descendants, not only to those who are of the Law, but also to those who are of the faith of Abraham, who is the father of us all,

In hope against hope he believed, so that he might become a father of many nations according to that which had been spoken, “So shall your descendants be.”

nor are they all children because they are Abraham’s descendants, but: “through Isaac your descendants will be named.”

That is, it is not the children of the flesh who are children of God, but the children of the promise are regarded as descendants.