Romans 4:9, 11, 13, 22

Now, think about it. Does this happiness come only to the Jews, or is it available to all who believe? Our answer is this: faith was credited to Abraham as God’s righteousness!

It was later that he received the external sign of circumcision as a seal to confirm that God had already transferred his righteousness to him by faith, while he was still uncircumcised. So now this qualifies him to become the father of all who believe among the non-Jewish people. And like their “father of faith,” Abraham, God also transfers his righteousness to them by faith.

God promised Abraham and his descendants that they would have an heir who would reign over the world. This royal promise was not fulfilled because Abraham kept all the law, but through the righteousness that was transferred by faith.

So now you can see why Abraham’s faith was credited to his account as righteousness before God.