This is why the promise is by faith, so that it may be according to grace, to guarantee it to all the descendants— not only to those who are of the law but also to those who are of Abraham’s faith. He is the father of us all
And he received the sign of circumcision as a seal of the righteousness that he had by faith while still uncircumcised. This was to make him the father of all who believe but are not circumcised, so that righteousness may be credited to them also.
then understand that those who have faith are Abraham’s sons.Now the Scripture saw in advance that God would justify the Gentiles by faith and told the good news ahead of time to Abraham, saying, All the nations will be blessed through you.