Not so serious, by a long shot, but still a carol for skeptics---already in Mudcat 2 Dec 2000--

God Rest Ye, Unitarians

God rest ye, Unitarians, let nothing you dismay
Remember there's no evidence there was a Christmas Day
When Christ was born is just not known, no matter what they say
Oh,, tidings of reason and fact, reason and fact
Oh, tidings of reason and fact.

There was no Star of Bethlehem, there was no angel song
There could have been no Wise Men, for the journey was too long
The stories in the Bible are historically wrong
Oh, tidings...

Much of our Christmas custom comes from Turkey and from Greece
From solstice celebrations of the ancient Middle East
We know our so-called "holiday" is but a pagan feast
Oh, tidings....