<soapbox>Christmas IS a religious holiday. You can choose not to celebrate it. You can choose to celebrate some other holiday at the same time of year (even something as stupid as the made up kwanzaa), but all that aside, no matter what one's religious beliefs may be, Christmas is a religious holiday. As a point of reference, I am not a religious person much at all. I do not consider myself to be a member of any organized religion. I do however realize that this time of year is especially 'holy' (whatever the right term is here) for most judeo-christian religions. I find it rather offensive and insulting that some people make up holidays at the same time of year to all but mock them those who do hold this as their holy time. So sad that people with an agenda bring race into this time of year.</soapbox>
Christmas, by its very existence, is an appropriation of the Roman solstice festival. Were the Christians mocking them?
Virtually all reasonable people believe a dude named Jesus from the town of Nazareth had a sociopolitical following around circa 30CE and that those followers morphed it into a religion after his death. (Whether this guy was actually God himself, or God's son, or just a good guy, or a total charlatan is something people can disagree on, but honestly, the variants in positions on that has nothing to do with this topic.) Virtually no reasonable person on Earth believes Jesus was born on December 25th, or any time in the month of December. There is, literally, not one reasonably-contemporary (to Jesus) Christian religious text that even claims as much. (In fact, virtually all evidence in the Gospel accounts points to Jesus being born sometime in autumn.) So the idea that someone else creating a "holy" day in December is insulting to Christians is just beyond inane.
One might also look to how virtually every culture looked at the time of the Winter Solstice as a hallmark time of the year (pagan solistice festivals, hannukkah, eid, Christmas, the very formation of the Julian calendar, Kwanzaa, etc) and reason that is why there is a huge number of "holy" events that sync up around this time. Its not an attack on Christmas, its a shared experience. Its as much about it being "the end of the year" (or "the end of the days with the lowest amount of sunlight") as it is anything else.
