What was Israel's role toward the Gentiles?
Israel's role was to be a light to the Gentiles, serving as God's channel of salvation to the ends of the earth. Yet they rejected this calling in unbelief, and the gospel then went to the Gentiles. This was foretold, but Israel refused.
Les teaches that Israel was to have been a light to the Gentiles, and Israel's Messiah would not have it unless they would believe. But they rejected it. Paul rehearses this, saying, 'I have set thee to be a light of the Gentiles, that thou shouldst be for salvation to the ends of the earth.' That was Israel's role, but they rejected it. So Paul says, seeing you put it from you in unbelief of everlasting life, we turn to the Gentile. When the Gentiles heard this, they were glad and glorified the word of the Lord, and as many as were ordained to eternal life believed.
For so hath the Lord commanded us, saying, I have set thee to be a light of the Gentiles, that thou shouldest be for salvation unto the ends of the earth.