I remember having this exact same tired conversation last Christmas with one of my Facebook "Friends." (Someone from Texas that I barely knew.) And this year, the same thing just happened again, with a different Texas person. She'd added a homespun Facebook message about "Jesus is the Reason for the Season" and about telling her little kid all about Jesus's birthday when the kid asked about why Christmas was at this time of year. Here's what I just responded on her Facebook page:
"Actually, the original holiday was December 21, the pagan winter solstice. Once the Christians overtook the pagans, they also overtook their holidays, and assigned Jesus an arbitrary December 25 birthday. (Most historians think he was actually born in late March.) So... Jesus really isn't the reason for the season. (If you've got a Christmas tree up in your house --- that's purely left over from the pagans and their tree-worshipping.)"
I'm going to get a lot of shit for that. Again. It's SOOO idiotic and profoundly tiresome. I challenge all real hard-core Christians to get that nasty pagan tree out of their living rooms once and for all. Be absolutely true to your crazy fanatic selves.