What does Romans 9:25 mean?
Once again, Paul reaches back into the history of Israel, preserved in the Scriptures, to support his argument. He has been showing that "not all who are descended from Israel belong to Israel" (Romans 9:6), in addition to insisting that God has chosen to show His mercy to some who are not Israel: to Gentiles.Here he quotes from a passage (Hosea 2:23) originally written about God's commitment to one day restore the exiled northern ten tribes of Israel. Under inspiration of the Holy Spirit, Paul applies Hosea's text to Gentiles, as well as Jews. Peter appears to have more loosely done a similar thing in 1 Peter 2:10.
In Paul's context, to those who were once not God's people and were not "beloved" by Him, He has now declared to be His people. He calls them "beloved." In this way, God has exercised His right to show mercy on whom He will show mercy, including the Gentiles.
Romans 9:19–29 deals with the issue of whether or not God's sovereign choice to bless some, and not others, is ''fair,'' in the way we often use that term. Paul's essential argument is that God is God, and as the Creator, He has the right to do as He wishes with His own creation. A potter can choose how to use clay, and that clay has no cause to complain that it was chosen for one purpose or another. In the same way, God has the absolute right to choose whom He will save. Quotations from Hosea and Isaiah are used to show that this sovereignty extends to God's plan to include Gentiles in the plan of salvation.
Romans 9 begins with Paul describing his anguish for his people Israel in their rejection of Christ. After describing all the privileges God has given to the Jewish people as a nation, Paul insists that God will keep those promises. However, not every person born to Israel belongs to Israel, he writes. God reserves the right to show mercy to some and not others, as Paul demonstrates from Scripture. God is like a potter who creates some vessels for destruction and others for glory. God has called out His people from both the Gentiles and the Jews to faith in Christ, the stumbling stone.