Who was the salvation Paul preached to the Gentiles based on?
Salvation for the Gentiles was based on Jesus of Nazareth, a Jew. Paul carried this message to the Gentile world, and the context stresses that this Jesus was Jewish. The Gentiles' salvation rested on that same Jewish Jesus, not on something separate.
Les explains that when Paul began going to the Gentile world, the salvation he preached was based upon that Jew, Jesus of Nazareth. Les stresses that Jesus was a Jew, and that the nation of Israel detested Him. Moses had foretold that another nation would come into fellowship with Israel's God, and Israel would hate them for it. The more Gentiles succumbed to the Gospel, the more the Jewish people fought it, except for a few. Les notes this is no different today, as seen in Israel's Law of Return, which tries to keep out Christians or Jewish believers in Christ.