Yeah, there is an ongoing debate about it...and the modern view is based on the actions of the Christian Church from the days of Constantine onward. Pretty wicked stuff was done to Jews by Christians who conveniently forgot that Jesus was a Jew.
The original Christianity was a bunch of Jews who believed Jesus was the Messiah. Even Paul continued to call himself a Pharisee throughout his entire life, going so far as to still sacrifice at the temple. He simply felt that the Goyim (non-Jews) did not have to follow the Law to also follow the Jewish Messiah.
In the early days, talking about Jesus in the synagogue was acceptable. It was the large number of non-Jews who were coming to the synagogue to hear about Jesus that bothered the Jews...and that was because of the odd belief that you can "catch" uncleanliness from a non-Jew (which has no Biblical basis that I can find).
The issue is that Christianity should not be a seperate religion at all...it was never intended to be, it was intended to be a form of Judaism...one which all Jews would eventually join.
As an aside, if a person's grandmother on their father's side is Jewish, their father is also Jewish...but they do not gain the religion at birth (the religion is passed from the mother). HOWEVER, the tribal affiliation is passed from the father (or the mother if the father is not Jewish), therefor the son/daughter gains the moniker of "Jew" for ethnic purposes. The Israeli supreme court has ruled that this person (someone who has a Jewish grandmother) is a Jew for immigration and citizenship purposes.
The REAL interesting part is that a person granted Jew status this way was not Jewish at birth (by religion), so if this person is a Christian or a Messianic Jew, the person never converted away from Judaism. The court ruled these people cannot be denied immigration and citizenship. 🙂
I know this because that is the category into which I fall.
