“To them belong the patriarchs, and from their race, according to the flesh, is the Christ, who is God over all, blessed forever. Amen.” -Romans 9:5
Not only to the Israelites, belong the adoption, the glory, the covenants, the giving of the law, the worship, and the promises,” but also the lineage and revelation of Christ, the Messiah, who is God over all and blessed for ever.
The Patriarchs were not only the fathers of the nation of Israel, but they were also progenitors of Christ. It was though their lineage that Messiah was given. In his letter to the Galatians, he explains, “Now the promises were made to Abraham and to his offspring. It does not say, “And to offsprings,” referring to many, but referring to one, “And to your offspring,” who is Christ” (Galatians 3:16)
We are to understand from this that Christ is the true Israel, he alone is the promised seed. The promises given to Israel were made that they might by the physical or human seedbed of the Messiah. Later, again, in his letter to the Galatians, he further explains: “But when the fullness of time had come, God sent forth his Son, born of woman, born under the law, to redeem those who were under the law, so that we might receive adoption as sons.” -Galatians 4:4–5
Also, the fact that Paul names Christ as God who is over all and blessed forever is more than a doxology of sorts, it’s a bold proclamation about the nature of Messiah. It is the boldest proclamation Paul makes to this end. In other letters, he remarks similarly but never this clearly.
In his second letter to the Corinthians he writes, “The God and Father of the Lord Jesus, he who is blessed forever, knows that I am not lying” (2 Corinthians 11:31).
And in his letter to the Christians at Ephesus he writes, “Blessed be the God and Father of our Lord Jesus Christ, who has blessed us in Christ with every spiritual blessing in the heavenly places,” -Ephesians 1:3