One of the most significant is the verse from Yishaya 7:14, which is their source for an "explicit" reference to a virginal birth of some sort, which they claim is their messiah.
Of course, this is, and always has been, entirely wrong for two reasons. 1) Context and 2) Mistranslation.
1) In the story taking place in the Navi, HaShem tells Yishaya to go to Achaz king of Yehuda and tell him not to worry about the recently announced alliance betwen Ephraim and Aram (who were conspiring against him) since they'll have their deserved downfall. So Yishaya is instructed to tell Achaz to ask HaShem for a sign as a proof that He is with Achaz. Even though Achaz refuses to ask of/test G-d, and Yishaya goes on to tell him about a child who will be born to a young woman (I think Rabbi Angel told us some meforshim think this refers to Yishaya's own wife), who will have special characteristics - and that will be the sign confirming the prophecy.
2) The word used in the posuk is "almah," which as any person who has a decent familiarity with Biblical Hebrew knows it means, "young woman," and not "virgin," which would be "besulah."
Christian theologians have taken this verse out of context for centuries, claiming it refers to the birth of a special child to a "virgin" who would later become their savior. Of course, none of that makes any sense whatsoever, since they got the translation wrong (perhaps deliberately) and why in the world would the birth of a special child hundreds of years later - this was during Bayis Rishon, and Jesus is believed to have lived during Bayis Sheini - serve as any sort of comfort to Achaz in his predicament?
Anyway, I recently read a very interesting article talking about the new "American Bible" that will be available next week. A large team of scholars have been working on updating the English translation of the Christian bible for a number of years now, and they've made a bunch of linguistic changes, one of which relates to this verse, and the specific mistranslation I mentioned above.
In a change in a passage in Isaiah 7:14 that foretells the coming of Jesus and his birth to a virgin mother, the 1970 edition's reference to "the virgin" will become "the young woman," to better translate the Hebrew word "almah."
So they finally decided to do the right thing and stop pretending "almah" is the same thing as "besula." Of course, since this actually undermines one of their principle sources for their doctrine of the virgin birth, they have to remark:
"The bishops and the Bible are not signaling any sort of change in the doctrine of the virgin birth of Jesus. None whatsoever," Sperry added.
Ha. Ha. Despite the fact that they are indeed pulling the proverbial rug out from underneath the doctrine - leaving it only to rely upon its pagan origins (think Hercules and other demi-gods born from a pagan deity and a human woman). At any rate, I think the change is rather fascinating. Of the many things I learned during Prof. Chaviva Levin's Medieval Jewish History course last year, medieval Christians worked pretty darn hard to show the "links" in the "Old Testament" that serve as a foundation or tie-in to the "New Testament." Given that context, it's a little strange to see modern Christians so willingly alter one of their important "sources."
P.S. For those wondering where the title of this post comes from - I came up with is based on another amusing word-choice change:
"Booty," which has come to have a sexual connotation, was changed to "spoils of war;"
I couldn't help but laugh...