This article in the Jerusalem Post is revealing, not for what it says about the particular group in discussion (JAMM; I’ve never heard of them before), but for what it says about the attitudes of others towards Jewish believers, including the attitude of the writer of the article (by the way she selects and arranges the material; the point of the article is to bring about the last sentence in the article). One essential assumption: you are not Jewish if you believe in Jesus. If the link goes bad with time, click here.