Then Abraham took his son Ishmael and all the slaves born in his house or bought with his money, every male among the men of Abraham’s house, and he circumcised the flesh of their foreskins that very day, as God had said to him.
If an alien who resides with you wants to celebrate the Passover to the Lord, all his males shall be circumcised; then he may draw near to celebrate it; he shall be regarded as a native of the land. But no uncircumcised person shall eat of it;
Circumcise yourselves to the Lord; remove the foreskin of your hearts, O people of Judah and inhabitants of Jerusalem, or else my wrath will go forth like fire and burn with no one to quench it, because of the evil of your doings.
Then he gave him the covenant of circumcision. And so Abraham became the father of Isaac and circumcised him on the eighth day, and Isaac did likewise to Jacob and Jacob to the twelve patriarchs.
whom God put forward as a sacrifice of atonement by his blood, effective through faith. He did this to demonstrate his righteousness, because in his divine forbearance he had passed over the sins previously committed;
It is those who want to make a good showing in the flesh who try to compel you to be circumcised—only that they may not be persecuted for the cross of Christ.
So then, remember that at one time you gentiles by birth, called “the uncircumcision” by those who are called “the circumcision”—a circumcision made in the flesh by human hands—
“Moreover, the Lord your God will circumcise your heart and the heart of your descendants, so that you will love the Lord your God with all your heart and with all your soul, in order that you may live.
This is the reason why Joshua circumcised them: all the males of the people who came out of Egypt, all the warriors, had died during the journey through the wilderness after they had come out of Egypt.