I desire my fellow Jews to be saved, and they have zeal, but not according to the truth of Jesus the Messiah. You can get righteousness by either obeying the law (no one can) or by faith in Christ.
How will anyone believe without being told? They have heard (Psalm 19:4) but have not yet understood.
How this is about Jesus
The law's purpose is to show righteousness and lead us to Jesus who kept it for us.
Verses 9-10 are an early and basic Christian creed. Jesus is Lord. God raised Him from the dead.
Believe and confess this, with your heart and lips and life!
Be zealous to bring the truth to your fellow countrymen. They've heard in a way already (even if they've never heard of Jesus), but they need to hear it again, perhaps more directly.