On that very day Abraham took his son Ishmael and all those born in his household or bought with his money, every male in his household, and circumcised them, as God told him.
“A foreigner residing among you who wants to celebrate the Lord’s Passover must have all the males in his household circumcised; then he may take part like one born in the land. No uncircumcised male may eat it.
Circumcise yourselves to the Lord, circumcise your hearts, you people of Judah and inhabitants of Jerusalem, or my wrath will flare up and burn like fire because of the evil you have done— burn with no one to quench it.
Then he gave Abraham the covenant of circumcision. And Abraham became the father of Isaac and circumcised him eight days after his birth. Later Isaac became the father of Jacob, and Jacob became the father of the twelve patriarchs.
God presented Christ as a sacrifice of atonement, through the shedding of his blood—to be received by faith. He did this to demonstrate his righteousness, because in his forbearance he had left the sins committed beforehand unpunished—
Those who want to impress people by means of the flesh are trying to compel you to be circumcised. The only reason they do this is to avoid being persecuted for the cross of Christ.
Therefore, remember that formerly you who are Gentiles by birth and called “uncircumcised” by those who call themselves “the circumcision” (which is done in the body by human hands)—
The Lord your God will circumcise your hearts and the hearts of your descendants, so that you may love him with all your heart and with all your soul, and live.