In Jesus, there is forgiveness from sins and freedom that the law can’t give. Freedom from a false identity and freedom from the tyranny of our own efforts.

The Jews were tempted to find their identity in their place as God’s chosen people rather than in the God who did the choosing. This is why they get jealous and angry when gentiles are excited about their inclusion in the gospel. If their identity was more in their God than their special place they would have rejoiced at more coming to Christ. 

This whole story is insane, but it follows Paul for the rest of his life - people who found identity in religion, separation, and authority get their whole identity attacked when God shows up with real freedom in something new.