Is there a difference between the nation of Israel and the church? Most Christians have made too much of the disconnect of their Jewish heritage instead of realizing that we are surrogate Jews. Christianity is the fulfilled Jewish church/ the fulfilled Israel.
Not all Jews are saved. They cannot be, as they have not accepted the Savior.
Yes there is a difference. I believe that Israel is still the center of all end times prophecy. I don't believe the church replaced Israel at all. That said, Jewish people do need to believe in Jesus Christ for salvation just like Gentiles. If you Google "replacement theology," you will find any number of articles on the subject.