Circumcision 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.
When Abram was ninety nine years old, the Lord appeared to him and said,“ I am El Shaddai—‘ God Almighty.’ Serve me faithfully and live a blameless life.
Then Abraham bowed down to the ground, but he laughed to himself in disbelief.“ How could I become a father at the age of 100?” he thought.“ And how can Sarah have a baby when she is ninety years old?”
And Abraham’s faith did not weaken, even though, at about 100 years of age, he figured his body was as good as dead— and so was Sarah’s womb.Abraham never wavered in believing God’s promise. In fact, his faith grew stronger, and in this he brought glory to God.