The Scriptures say the same thing about Abraham: "Abraham believed God, and God accepted Abraham's faith, and that faith made him right with God."
So you should know that the true children of Abraham are those who have faith.
The Scriptures, telling what would happen in the future, said that God would make the non-Jewish people right through their faith. This Good News was told to Abraham beforehand, as the Scripture says: "All nations will be blessed through you."
So all who believe as Abraham believed are blessed just as Abraham was.