LINK: Romans 10
Paul had a great desire to see his fellow Jews come to salvation. But instead of seeking God and His righteousness, the Jews had historically sought their own self-righteousness through the Law. This will never save them, nor will it save anyone else, for that matter.
This is the key: "if you confess with your mouth Jesus as Lord, and believe in your heart that God raised Him from the dead, you shall be saved; for with the heart man believes, resulting in righteousness, and with the mouth he confesses, resulting in salvation" (Rom 10:9-10).
So, you might ask as Paul does in verse 18, "What about those who have never heard?" Indeed, they have heard. God has sent evidence of Himself all over the world (remember chapter one?).
Or one might object, "The Jews didn't know, did they?" Even as far back as Moses, God predicted to the Jews that they would reject Him and He would make Gentiles His people (vs 19). God would show Himself to the Gentiles even though they didn't look for Him (vs 20). But as for Israel, God demonstrated love to them generation after generation, yet they continued to be disobedient and obstinate toward Him (vs 21).
So the Jews "had a chance," so to speak, but what about the heathens? How can they call on Jesus for salvation if they don't believe in Him? How can they believe in Him if they've never heard of Him? How can they hear of Him unless somebody goes to them and tells them? How can someone go and tell them unless they are sent?
What role are you playing? Are you one who is going? Are you one who is sending? Are you telling people about Jesus? There are still many people groups around the world who have never heard of Jesus. They have no Scripture in their language, neither are there any believers among them. How are they going to know?
Take a look at the Joshua Project, Frontiers, New Tribes Mission, Wycliffe Bible Translators, other missions you know of, or your church's mission organization for ideas of how you can get involved.
Lord, open our eyes to see that it's all about Jesus and faith in Him. We are not and never will be righteous on our own efforts. But it's through our faith in Jesus that You make us righteous. This is truly Good News! May we share the good news of Jesus around the world. Amen.