Abram and Sarai get new names to recognize God’s promises to them. God also requires all the males of Abraham’s household to be circumcised. The ritual of being circumcised symbolized the special relationship God has with Abraham and his descendants.
Paul refers to Abraham’s circumcision in Romans 4:11, emphasizing that Abraham was made righteous by his belief in God’s promises back in chapter 15 before he was circumcised. Paul’s point was that people have always been made righteous by faith, not by following rules or completing religious rituals. Abraham’s circumcision was important because God asked Abraham to be circumcised, but it wasn’t what made him righteous. The same is true for us. It’s important to obey God, but our obedience isn’t how we are adopted into God’s family. It’s our faith in what God has told us that matters most.