That way you’ll be the children of your Father who is in heaven. He causes his sun to shine on bad people and good people, and he sends rain on those who do right and those who don’t.
That’s why the promise comes by faith, so that it can be based on God’s grace and be guaranteed to all of Abraham’s children. That means not only those who are his children under the law, but also those who are Abraham’s children because have the same faith that he did. He is the father of us all.
And Abraham is also the father of those who are circumcised, but who aren’t just circumcised—they also follow in the steps of our father Abraham, who had faith before he was circumcised.