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

And, predicting that God would consider the Gentiles right with Him by [their] faith, the Scriptures previously recorded [this promise of] the Gospel to Abraham by saying [Gen. 12:3], "All nations will receive a blessing through your descendant [i.e., Jesus]."

So then, all those who have faith [in Jesus] receive a blessing along with Abraham, a man of faith.

[This happened] so that the blessing [promised] to Abraham might be received by the Gentiles through [the person and work of] Christ, so that we might receive the promised [gift of the] Holy Spirit through [our] faith [in Jesus].

Now [specific] promises were made to Abraham and to his seed [i.e., descendants]. [God] did not say "seeds" [plural] as though He were referring to many persons but "seed" [singular] showing that He meant one [descendant]; [Gen. 13:15 says] "And to your seed," referring to Christ.

Here is what I am saying: The Agreement originally made by God [with Abraham], with its attending promises, was not canceled when the law of Moses was given some four hundred and thirty years later.

For if the inheritance [of never ending life] can be obtained by [obeying the requirements of] the law of Moses, it would not come from the promise [of God]; but God provided [this inheritance] for Abraham according to [His] promise.

And if you belong to Christ, then you are [truly] Abraham's seed [i.e., his spiritual descendants] and thereby [you will] inherit what was promised to him [i.e., God's blessings].

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].

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

What does the Scripture say about this matter? [It says, Gen. 21:10-12], "Get rid of the slave woman [Hagar], with her son [Ishmael]; for the son of the slave woman [Ishmael] will not inherit [what God promised to Abraham and his descendants], along with the son of the free woman [i.e., Isaac]."