Romans 4:16

And Jesus said to him, “Today salvation has come to this house, because he, too, is a son of Abraham.

even the righteousness of God through faith in Jesus Christ for all those who believe; for there is no distinction;

being justified as a gift by His grace through the redemption which is in Christ Jesus;

since indeed God, who will justify the circumcised by faith and the uncircumcised through that faith, is one.

and he received the sign of circumcision, a seal of the righteousness of the faith which he had while uncircumcised, so that he might be the father of all who believe without being circumcised, that righteousness might be counted to them,

That is, the children of the flesh are not the children of God, but the children of the promise are considered as seed.

For I say that Christ has become a servant to the circumcision on behalf of the truth of God to confirm the promises given to the fathers,

so know that those who are of faith, those are sons of Abraham.

in order that in Christ Jesus the blessing of Abraham might come to the Gentiles, so that we would receive the promise of the Spirit through faith.

Now the promises were spoken to Abraham and to his seed. He does not say, “And to seeds,” as referring to many, but rather to one, “And to your seed,” that is, Christ.