So it doesn't happen again. If you understand the past you can see the future.
Anti-semitism says much about the nature of the evil in a person or group. For believers in the divinity of Jesus, hatred of the Jews is a statement of hatred of God and, as such, has a specific source.
The degree of that hatred and how it manifests itself provides additional clarification of, well, the kind of evil that is at the source of that hatred.
Beyond that, it is one of those things that one must find out for himself.