The quick answer is of course that Christmas is a celebration of the birth of Jesus, and only Messianic Jews believe that Jesus was the messiah.Actually, a few Jewish people do celebrate Christmas, but not in the same way Christians do, and it’s still pretty rare. According to a 2013 Pew Research poll, about 30% of Jewish respondents had a Christmas tree in their home. Usually this happens when there is an interfaith family or when the Jewish person is not practicing as a religious Jew.This isn’t to say that Jewish people across the world are attending Christmas services and celebrating the birth of Christ, but don’t assume that your Jewish friends wouldn’t come over for a Christmas Eve meal with you. For them, it would be more of a cultural celebration, but it can still be a celebration. It would be best to ask them directly if it’s okay to say “Merry Christmas” or if they are interested in participating in Christmas celebrations with you.