And if you are Christ's, then you are Abraham's seed, and yours is the heritage by the right of God's undertaking given to Abraham.

Now, brothers, you [Christians] are children of the promise [made to Abraham. See 3:29] just like Isaac, [Abraham's son] was.

then understand that those who have faith are Abraham’s sons.

For it is written in the law about Abraham's two sons [Gen. 16]; one [was] by his slave woman [Hagar] and the other by the free woman, [his wife, Sarah].

And the Scripture, anticipating God's justification of the Gentiles by faith, announced the gospel to Abraham beforehand in the words, In thee shall all the Gentiles be blessed.

[An example of this is] Abraham, who believed God's [promise] and [because of such faith] he was considered right with God.

So then they who are children of faith are blessed with Abraham the faithful;

to the end that in Christ Jesus the blessing of Abraham might come upon the Gentiles, so that through faith we might receive the promised Spirit.

Now it was to Abraham that the promises were spoken, and to his offspring. God did not say, "offsprings" as if speaking of many, but "and to your offspring," as of one; and this is Christ.

For if the inheritance comes from law, it no longer comes from a promise; but God did give it as a free gift to Abraham by a promise.