The Roman Catholic teaching, albeit somewhat confusing, states (in simple terms) that Christians, by definition, accept Jesus as their Lord and Savior; that's the only requirement to being 'Born Again'. The Bible says it this way:
'that if you confess with your mouth the Lord Jesus and believe in your heart
that God has raised Him from the dead, you will be saved.' (Romans 10:9).
That's it. No more - no less
There's much other documentation in the Bible about it, but that's the bottom line.
Jews never did accept Christ, so they are still under the Law. That does not mean that everything terrible that has happened to them is the result. On the contrary, as Scott said, What has happened to them is because Sin is still in the world. Satan is still Prince of this world, and he wants them dead! With them dead, God can't fulfill His promise to them (so Satan thinks). That's why the Middle East is in such a mess - Satan is still trying to destroy them. However, he's only doing God's will. I read the end of the book - we win
Don't attempt to equate what is happening to the Jews to some punishment by God for their unbelief. He doesn't work that way. They will eventually be 'reinstated' into His graces, but must go through Tribulation (the Great Tribulation) to get there. What we are seeing today in the Middle East (and around the rest of the world as well) is only the beginning.