To repeat an earlier post, the question is "What is Israel." Paul talks about how Jews that reject Christ are pruned from the branch (and gentiles who accept are grafted on). Here is my earlier response:
Well, not exactly. (I wish; I am an ethnic Jew.)
To quote Paul on this topic:
. . . For not all who are descended from Israel are Israel. Nor because they are his descendants are they all Abraham's children. On the contrary, “It is through Isaac that your offspring will be reckoned.” In other words, it is not the natural children who are God's children, but it is the children of the promise who are regarded as Abraham's offspring . . . "
To make a long theological point very short, Christians are adopted into the promise, and Jews, while still the Chosen People, don't necessarily get the benfit of the promise, post-Christ, unless they accept Christ just like everyone else.
What I said. :)