There's another cliche that we have to be aware of and be dillegent to overcome, and that is the idea that anyone who keeps the Sabbath, Feasts, kashrut, etc., does so in order to be saved "by the law" instead of trusting in "grace." This is why I take a personal demand against Gentile Christians (Jewish Christians are another matter) off the table and rephrase the argument: "So you're saying that God sent the King of the Jews to tell Jews to stop being Jewish?"
Most Christians that I get a chance to speak to are rightly horrified that this is the practical implication of what they've always assumed about the NT. They're not antisemitic; in fact, most true Christians love the Jews, even if only abstractly. They just never considered how their understanding of the NT plays out in that regard.
Shalom
We surely don’t want to lose our right to eat bacon, and worship Tammuz on 12/25, and Ishtar and the lovely rabbit eggs...