Jewish people who believe in Jesus go by many terms -- and it usually depends upon the preference of the person. Messianic Jew or Jewish believer is synonymous in many respects. Some might disagree and focus on the fine point difference that Messianic Jews are more culturally observant in Jewish practices (i.e., keeping Kosher, wearing a kippah) than Jewish believers. They would be mostly correct but the two terms are really synonymous at their most basic level and it is really an issue of preference. The term "Completed Jew" has been used in the past but is out of vogue because it can cause such a negative reaction in the Jewish community who do not yet believe in Jesus as Messiah. The reason for the reaction is that they perceive that they are being marked as "half Jewish" and this is an offense. Therefore, Tzedakah Ministries and myself personally avoids using this term. And of couse there are Jewish Christians, and in fact many who prefer Jewish believer will often also use the term Jewish Christian. And besides all of that, let me list a few Jewish Christians -- Matthew, John, Peter, Thomas, Paul, etc. It is not wrong to use the term Jewish Christian because it is a response to those who inaccurately say that if a Jewish person become a Christian, a person automatically stops being Jewish.