Romans 9 focuses on God's sovereignty in choosing His people, both in Israel and among the Gentiles. The chapter begins with Paul expressing his deep sorrow and anguish over the unbelief of many Israelites, even though they were God's chosen people. He acknowledges that while Israel had been given many blessings, the Gentiles were now also receiving salvation through Christ.Paul then goes on to explain that God's promise has not failed just because Israel is not responding to it, for not all who are descendants of Israel are "true Israelites." Rather, God is sovereign in choosing who will be saved, and His mercy is not based on human works, but on His own purpose and grace.Paul illustrates this point by referencing the stories of Jacob and Esau and of Pharaoh, showing how God's purposes were accomplished through them, despite their character or merit. He concludes the chapter with the idea that salvation is available to both Jews and Gentiles, but that some reject it while others receive it by faith.