Please keep the reason for the season in Christmas by saying "Merry Christmas". Please don't take Christ out of Christmas by saying Happy Holidays or Merry Xmas.
Christ was crucified on the cross & took the pain/sacrifice for us that we could be forgiven of the sins we commit everyday and can be forgiven (just try very best not to backslide). If it weren't for The Father sending Christ into the world there would be no Easter, Thanksgiving, or Christmas.
That's the very least we could do.
Thanks for your time, have a very safe & Merry Christmas