Romans 9  Paul has great sorrow and grief because of the unbelief of the Jews.  They had the Law, the covenant, they had the glory, the temple, and the promises of God.  They had the Messiah Himself, but they would not believe.

Paul's point here is that salvation does not come because of what you do or who you are.... It depends only on God.  " So then it does not depend on the man who wills or the man who runs, but on God who has mercy." (v16)

Abraham had two sons - the son of the flesh and the son of the promise, Isaac.  God chose Isaac.
Isaac had two sons - Jacob and Esau.  God chose Jacob.

God chooses to "have mercy on whom He desires, and He hardens whom He desires." (v18)
God chose to call Gentiles to faith and make them His people too.
God chose to make faith the way to salvation and righteousness.
God chose to make Jesus Christ the only way, the only Name by which we can be saved.

Father in heaven, we hallow and honor Your Name.  You alone are Sovereign and Mighty, God of heaven and earth.  You alone choose to have mercy on us, to call us to faith in Jesus Christ, to believe that He is Lord.  That He died on the cross and was buried and rose again, that we might be saved.
Thank You for the great riches of Your mercy and grace.  Be exalted, lifted us, and glorified today and forever. amen.