Galatians 3:7 Know ye therefore that they which are of faith, the same are the children of Abraham
What an astonishing truth this verse holds! And every believer in Christ is a partaker of its truth! When God promised Abraham that his descendants would be in number as the stars of the heavens (Genesis 15:5), it was a two-fold promise. One, that Abraham would indeed father a physical, ancestral nation, that being Israel. But also, that those who are redeemed through repentance of sin and faith in Christ Jesus, are similarly children of Abraham in the eyes of Almighty God.
This is why we are told that in Christ Jesus, there is neither Jew nor Greek (non-Jew), for we are made part of the family of God through His Son (Galatians 3:28). Consider how when God made this promise to Abraham, God had you and I in mind! At that point in time, Abraham was an old man without any children of his own, with a body closer to death than youth (Romans 4:19). Yet God called this frail old man, to be the father of those in the faith. He did this so that all those called as adopted sons and daughters of God, may share in the inheritance of Christ Jesus, the firstborn among the brethren of God (Romans 8:29).
Never take for granted the immensity of this adoption into the family of God. It was an adoption promised long ago, and though Abraham would not see the fullness of the promise in his mortal flesh, he believed the promise of God. Because of that simple faith, he now enjoys eternal peace and glory. As his children in the Spirit, we will join him one day in heavenly glory. All by the Lord Jesus Christ, our blessed Saviour and Redeemer. Amen.