Romans 4:11-12

11Circumcision was a sign that Abraham already had faith and that God had already accepted him and declared him to be righteous—even before he was circumcised. So Abraham is the spiritual father of those who have faith but have not been circumcised. They are counted as righteous because of their faith.

12And Abraham is also the spiritual father of those who have been circumcised, but only if they have the same kind of faith Abraham had before he was circumcised.