'Posterity' in the Bible

who, as regards His human descent, belonged to the posterity of David,

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

Under utterly hopeless circumstances he hopefully believed, so that he might become the forefather of many nations, in agreement with the words "Equally numerous shall your posterity be."

nor because they are Abraham's true children. But the promise was "Through Isaac shall your posterity be reckoned."

In other words, it is not the children by natural descent who count as God's children, but the children made such by the promise are regarded as Abraham's posterity.

And just as Isaiah foretold,“Unless the Lord of Sabaoth had left to us a posterity,We would have become like Sodom, and would have resembled Gomorrah.”

I ask then, Has God cast off His People? No, indeed. Why, I myself am an Israelite, of the posterity of Abraham and of the tribe of Benjamin.