Peace be with you, in the New and Old Testament, we have come to understand clearly that Abraham and Sarah are one flesh and they are Father and Mother of all nation, to Jews and Gentiles. Also because of his faith in the Living GOD, the same GOD who proclaimed Abraham, in HIS very own Word (CHRIST), Abraham as the 'Father of Faith'.
GOD said to Abraham; "I will make an Everlasting Covenant with one of your 'offspring'............................"
The blessing for the Gentiles is that even though they were only able to receive the crumbs that fell from the children of Israel's table but automatically they who believe have also become the part takers of the common wealth of Israel that is according to GOD'S promise and Covenant with Abraham, Isaac and Israel (Jacob), even Everlasting Life in the new Heaven and earth to come, only through that one offspring called 'CHRIST' SON of the LIVING GOD.
GOD sacrificed HIS only begotten SON for a human faithful friend called Abraham, as HE had planned that HE would fulfill the promise through Abraham and Sarah's 'descendant', that is by;
a) First, delivering Abraham and Sarah from barrenness.
b) Second, HE made all sure and HE fulfilled the Everlasting Covenant with one and through one of Abraham's offspring who is JESUS, born in Bethlehem, son of Joseph and virgin Mary, who grew to put on and take on as the CHRIST, SON of the LIVING GOD and fulfilled faithfully the promise of GOD to Abraham and also established that promised Covenant forever and ever and these all have now come to past, even till today, is to be a born again Gentile's unworthy and undeserving witnessing of the Living Lovely Truth, to the ignorant others remaining in the world.
That is why it is clearly written to the Gentile Christian, not to be proud of themselves, who have become only 'part takers', for now grafted to the New Israel tree and later is possible to be cut off again and be left to be withered.
As it is written; "If you have ears, listen and pay attention."
May GOD the FATHER of our LORD JESUS CHRIST bless all those who are with such ears, to be led to obedience in spirit and truth worship.