What does Romans 10:9 mean?

Romans 10:9–10 are two of the great salvation-related verses in the entire Bible. It's important to understand their context in this chapter.

Paul has just concluded quoting from Deuteronomy 30:11–14. There, God says to Israel that His command for them is not hidden or far away; it is already in their mouths and hearts. Paul has written that this is true, as well, for the "word of faith" in Christ. This "word of faith" is a reference to the gospel: the message of salvation by grace through faith in Jesus Christ. This message is near Israel's mouths and hearts.

Now Paul clarifies what this word of faith is; he explicitly describes what the Jewish people of his day should welcome into their mouths and hearts. He writes that instead of seeking to become righteous by following the law, they should confess with their mouths that Jesus is Lord. He is the Messiah. Also, they should believe in their hearts that God raised Jesus from the dead. If they do those things, they will be saved, Paul writes.

We should not necessarily take these two conditions as Paul's final statement on the plan of salvation or how to become a Christian. He has been clear that faith in Christ, including Christ's place on the cross as our substitute in the payment of our sin, is the key to being declared righteous by God. These two conditions—belief in Christ's resurrection from the dead and a verbal confession of His place as Lord of all—appear to serve as evidence that our faith is in Christ. Anyone who trusts in Christ for his or her salvation is sure to agree that Christ is Lord and that He was raised from the dead. That person will be saved, Paul writes.