But faith and circumcision are the same thing.
Faith is Torah.
No Yehudim ever believed that the blood of a lamb could save. They came as penitents in faith with their innocent little beasts. The Christian idea of simply invoking the name of Jesus to be saved falls miserably short of the Torah's idea of faith. It is obvious that the Greek manuscripts we are led to believe were the original are probably not so. Show me your faith without your works, and I by my works will show you my faith.