Abraham lived before the law was handed down. God told Abram to leave his family and his country. Abram did not question God about how or where, he just did what God asked him to do. Because Abram believed God, it was reckoned to him as righteousness. Abram was renamed Abraham. It was quite amazing that Abram would trust a God that he hardly knew. Today, even with the Holy Spirit dwelling in us, how many of us would leave everything and go to wherever God would lead? Abraham did this by faith in God. When God told Abraham that “all nations” would be blessed in Him, it was a foreshadowing of our being saved by grace through faith. Yes, God picked a certain lineage and nation to carry His Name forward and made a covenant with them to do so. That covenant and the law that followed was not meant to exclude other nations or set aside the promise God had made to Abraham. It was meant to show all nations that we need a Savior. And at just the right time, God sent His Son to be that Savior and Redeemer.
4 But when the fullness of the time came, God sent forth His Son, born of a woman, born under the Law, 5 so that He might redeem those who were under the Law, that we might receive the adoption as sons.—Gal. 4:4,5 (NASB)