Hi, Mark —

Thanks for the question.

First of all you are incorrect, the prophets in the Bible come from all the tribes of Israel, not just Judah. Therefore, they were not all Jewish. If you called Isaiah a Jew, he'd look at you, like you had four heads.

The term Jew, was a term that we begin to see after the return of the tribe of Judah from the Babylonian captivity. The other (11) eleven tribes were scattered by the Assyrians early and while they are Israelites, and have the same religion, it is incorrect to call them Jews.

Now the reason the Prophets were all Israelites, is because God promised that redemption would come from the seed of Abraham and Sarah. Israel was, and is, the nation that was called to be a light to the gentile (pagan) nations.

Today Israel, (theologically speaking), is the Church. In and through Jesus Christ, all men are called into the Universal People of God, or into the One, Holy, Catholic, and Apostolic Church.
That doesn't mean Israel, the nation, is still not part of God's plan; it is! However, St. Paul tells us
that if we be in Christ Jesus, we are sons of Abraham by faith. (Galatians 3:29)

Scripture records Salvation History and we know again, from St. Paul, that Salvation comes from the Jews (John 4:22) because Jesus is a Jew. As he writes in Romans:

16 I'm not ashamed of the Gospel, for it is God's power unto Salvation, for Jews first and then to the Gentiles.

Romans 1:16

John