There's no such thing as a Jewish Christian.
Just like there are no Christian Muslims, Buddhist Christians, Muslim Hindus, etc.
If Jewishness was based purely on blood as you seem to suggest it should be, Israel would be required to take in millions of Muslims who were once Jews and who were forcibly converted. That would be insane.
The "Messianic" Jewish movement is not Jewish at all. It is financed by the Southern Baptist convention as a way to deceive Jews into apostasy. They deserve no recognition by Israel or the Jewish people in any way. They certainly deserve recognition by Protestant Chrisianity, but not Judaism and not Israel. They go after homeless people, mental patients, old people in retirement homes. I’ve seen it myself.
When I lived in Israel, there was a missionary in my neighborhood. He brought a girl from South Africa who began sleeping with different homeless people in order to turn them Christian. I saw it with my own eyes. She would hang around outside the soup kitchen in a mini-skirt and heels flirting with these homeless and mentally disturbed lonely men.
I spoke to one of the guys who converted. He said that she was sleeping with him and 4 other guys from the soup kitchen. You may not be aware of this, but these are the tactics that missionaries use.
They also dress up as orthodox jews and ask to check the mezuzot(small torah scrolls that are affixed to doorposts) of secular Jews. Then they take the scroll, erase the name of God and put a cross in place of the name of God. I have seen numerous examples of their handiwork.
Before you automatically defend that, THINK ABOUT IT. Is that what you want to do in this world, erase the name of God and put a Roman murder device in place of God’s holy name?
But then again, this issue highlights one of the main problems with a Jewish-Christian alliance.
Christians are required to proselytize in all places to all people. I understand that this is your belief, but I hope you don’t think that I am crazy enough to help you convert my people to your religion? How would you like it if I went around trying to convert your children, your elderly, your fellow Christians? You would like it around as much as we do.
I wish that we could call a truce. Jews will not try to convert and Christians will not try to convert Jews. That is ultimately fair.
But instead, Christians spend tens of millions of dollars a year trying to convert Jews. Jews are required to discourage conversion. Therefore, we are at an absolute disadvantage and I hope you don’t think that we’re going to add to that disadvantage by accepting Christians whose parents or grandparents were Jewish as “Jews”.
That would be insane.
And as far as Christian support of Israel is concerned, if you think that you are going to help Israel and then say “Now you owe us, Accept Christian Jews as Jews or we’ll stop supporting Israel.” Please STOP supporting Israel immediately. We don’t want or need such “support”. It says in the Torah, “Am levadad yishkon” Behold, it is a nation that shall dwell alone.
Israel will survive with or without Christian support. Israel will survive because it is God’s will that it survive.
The fact that there are any Jews alive today in 2007 is an absolute miracle. We were almost wiped out by Christians multiple times, so please excuse me if I don’t help your missionaries to wipe us out spiritually.