Dear Rabbi Simon,
The first of the Seven Noachide Laws is not to worship false gods. As Christians worship Jesus (who is a false god according to Jewish law) would they have no place in the World to Come?
This rather fundamental question is subject to divergent positions in the rabbinic tradition. While the straightforward view would confirm your suggestion, ie that worship of Jesus as the son of G-d (absit!) is a form of idolatry, there are those who maintain that such a distorted view of the One G-d, while misguided and forbidden to Jews, is nonetheless permitted to gentiles.
It would seem that this latter opinion is rather convoluted and apologetic. Still, it may allow a lot of people to still hope for a portion in the Next World, so let’s not dismiss it outright!
Rabbi Rashi Simon