It is a matter of faith, not circumcision

^9a Now the question, an important one, arises: is this happiness for the circumcised only, or for the uncircumcised as well?

^9b-12 Note this carefully. We began by saying that Abraham’s faith was counted unto him for righteousness. When this happened, was he a circumcised man? He was not, he was still uncircumcised. It was afterwards that the sign of circumcision was given to him, as a seal upon that righteousness which God was accounting to him as yet an uncircumcised man! God’s purpose here is twofold. First, that Abraham might be the spiritual father of all who since that time, despite their circumcision, show the faith that is counted as righteousness. Then, secondly, that he might be the circumcised father of all those who are not only circumcised, but are living by the same sort of faith which he himself had before he was circumcised.