Summary: The argument turns from how to be saved to why Israel wasn't saved with these verses. Like so many people today the Jews had rejected God's plan to save the world, they had rejected Jesus as the Messiah basically because they had rejected God's Word.
ROMANS 10: 17-21
THE REJECTION OF THE WORD
We have just been advised in this passage dear friends that if you are seeking salvation you must be a hearer of the Word. We are to keep in mind that it is the Word of God that we need to hear, because the word of man cannot save you. It may delude you. It may give you false hope and security; but the hearing that saves is the hearing which comes by the Word of God. We should take care then, that we do not run hither and thither just because of the cleverness of certain speakers; but keep to the Word of God, for "faith cometh by hearing, and hearing by the Word of God."
The argument turns from how to be saved to why Israel wasn't saved with these verses. Like so many people today the Jews had rejected God's plan to save the world, they had rejected Jesus as the Messiah basically because they had rejected God's Word. Paul's attention returns to the Jews as it concerns hearing and responding to the Word of God, specifically the gospel of Jesus Christ. The final verses of Romans 10 deal with more excuses for the Jews not understanding the Messiah's mission or what was going to happen if they continued to reject God's message and messenger. A series of O. T. quotations reinforces the outcome of Israel's rejection.
I. THE HEARING OF THE GOOD NEWS, 18.
II. THE OPERATION OF THE GOOD NEWS, 19-20.
III. THE REJECTION OF GOD , 21.
Now the unbelief of Israel came as no surprise to some like Isaiah (53:1) as verse 16 states. Some though might not be prepared to accept that they were guilty of unbelief because they believed they had not properly heard. Someone might argue, "Yes, Israel heard but she did not understand that God purposed to offer righteousness by faith to all mankind." So Paul raises and answers the possibility in verse 18. "But I ask: Did they not hear? Of course they did: "Their voice has gone out into all the earth, their words to the ends of the world."
God had sovereignly chosen the nation Israel in the past. He made Himself known to them, but they still rejected Him. Paul splices into Psalm 19 to make his point. The first half of Psalm 19 references how God speaks to us through His creation. The second half of Psalm 19 teaches how God reveals Himself to us through His Word. Paul's conviction is that Israel has been the recipient of a wide-ranging testimony to Jesus as the Messiah (Rom. 15:19, 23).
The preaching of God's good news went forth amongst the Israelites. Wherever they went, the gospel seemed to follow them like their shadows. They could not escape from it, but they did not believe it. Colossians 1:23 states, "...the gospel that you have heard, which was proclaimed in all creation under heaven..."
This same truth is emphasized so strongly in the first chapter of Romans. For "they suppress the truth in unrighteousness…that which is known about God is evident within them; for God made it evident to them. For since the creation of the world His invisible attributes, His eternal power and divine nature, have been clearly seen, being understood through what has been made, so that they [unbelievers] are without excuse" (1:18–20). All men have both internal and external evidence of God. Just as the heavenly bodies reveal themselves to all and preach God's majesty through God's natural revelation, so His gospel speaks to all the earth with His special revelation. God cannot be unfair or unjust. Those who refuse to trust in Him do so because they "suppress the truth in unrighteousness."