I post this every year about this time.
Can You Wish a Witch a Merry Christmas?
Granted I have run into the occasional radical Pagan with a chip on their shoulder who gets all in a humph! because someone dared wish them a Merry Christmas – I tend to ignore them and suggest you do the same.
If you are most comfortable saying Merry Christmas, then by all means wish people a Merry Christmas in the December holiday season. In the same way, if you are more comfortable, wish someone a Happy Yule, a Prosperous New Year, a Happy Hanukkah, or even a Merry Diwali.
In all ways, we are saying the same thing as we celebrate the turning of the Earth through the seasons. It doesn’t matter what words you use, as long as you fully mean them.