It was because Abraham trusted in God that God erased the record of his sins and promised him many blessings. So what God promised is guaranteed to all, both Jews and non-Jews, who trust in God as Abraham did.

Romans 4:13-17a

13 God promised Abraham and his descendants that they would receive the blessings that he promised to give to the people in the world. But when he promised that, it was not because Abraham obeyed the laws that God later gave to Moses. Instead, it was because Abraham believed that God would do what he promised that he would do. As a result, God erased the record of his sins. 14-15 14-15If we think that it is those who obey God’s laws who will receive what he has promised, it is useless for us to trust in him. And what he promised is worthless. Remember that it is stated in God’s law [PRS] that he will punish people who do not perfectly obey them, and remember that wherever [MTY] laws exist, people disobey them [LIT]. 16 So it is because we trust in God that we will receive the things that he has promised. It is not because we perfectly obey God’s laws. He wants ◄to erase the record of our sins/to declare us no longer guilty► without our earning it. As a result, what God now promises, he guarantees to give to all people who are Abraham’s spiritual descendants. He promises to do that not only for us Jewish believers, who have God’s laws and trust in him as Abraham did, but also for those non-Jews who do not have God’s laws but who trust in him as Abraham did. Abraham is the spiritual ancestor of all of us believers. 17 What is written {What Moses wrote} in the Scriptures about what God promised Abraham shows that this is true. God said to him, “It is in order that you (sg) may be the ancestor of many ethnic groups that I have chosen you.”