Muslim/Islam

The way to approach a holiday that is not your own is to use it as a teaching mechanism if you are worried about your children "fitting in" in a largely Xtian community (or, conversely, if you are worried about them fitting into a Muslim community). Celebrate the holiday from an anthropological perspective, teach the reasoning for the symbols and actions (trees, creches, fasting, whatever) and keep your own holidays as a primary, important, familial/friends focus.

There is such a thing as a "secular" Christmas, with the pagan tree and the guy down the chimney (the Japanese excel at it) -- and Santa Claus (St. Nicholas) was said to be Turkish.

If you do not freak out, they won't either. Kids are smarter than we give them credit...