Paul makes it abundantly clear of his passion and compassion for the Jewish people for their salvation. He knew they had “a zeal for God, but not according to knowledge.” They were ignorant of God’s plan for righteousness that the law was intended to lead them to faith in Christ; they insisted on “earning” favor with God on the basis of “their works”. Christ came to “end” the work mentality to earn righteousness through the law for those who believe in Jesus Christ. It wasn’t the law was bad or evil, rather the ones to whom it was given used it for religious purposes.
There isn’t coming “another” Messiah, He has already come and His name is Jesus! For most of the Jewish nation, they anticipated a political Messiah rather than an eternally spiritual Messiah. Rather than working and thereby earning through works, favor with God; the doorway to faith was through a heart transformation that had a parallel verbal confession of faith in Jesus Christ. Note the sequence in verse 10; heart transformation and THEN verbal confession of faith in Jesus; when enjoined together result in “salvation”.
Paul quotes Isaiah, reminding them “whoever” would place their trust and faith in Christ would “not be put to shame”; followed by “whoever” would call on the name of the Lord would be saved. This invitation was never intended to be based on ethnicity, gender, race or education; rather “whoever”, any people group.
The obvious question to such a bold statement was presented by the apostle in a series of questions that would ultimately lead to taking personal responsibility to be a messenger of the faith in Christ to work sites and other locations in the course of one’s life. Those who bring that message have good looking feet! That’s you and I when we give an answer of the hope that lives within us; both to Gentiles and Jews alike.
The only means of receiving faith is through hearing the word of God. That message was first proclaimed to the nation of Israel and then the entire earth. By extending the invitation to the Gentiles, it will be a time (on a limited scale now, but greater in the days ahead), it would be an motive for provocation to seek the truth by Israel and thereby be saved as well.
Even though the Gentiles were seeking Him, they found him; they didn’t ask for proof, but discovered God. Throughout their history, up to the coming of Jesus; the Father had been faithful to demonstrate faith, patience and MERCY to the Jewish people. They could have received Him, but resisted and rejected Him outright.