(Rom 4:11) “ And he received the sign of circumcision, a seal of the righteousness of the faith which he had yet being uncircumcised: that he might be the father of all them that believe, though they be not circumcised; that righteousness might be imputed unto them also:” Abraham had two types of children, those of the flesh and those of the spirit. The physical children took on the outward sign of circumcision, the spiritual the circumcision of the heart: (Rom_2:29) “But he is a Jew, which is one inwardly; and circumcision is that of the heart, in the spirit, and not in the letter; whose praise is not of men, but of God.”