glad tidings of reason and fact

Apparently the new reason-for-the-season is Reason itself.

My mother responds to my current theme by forwarding me this in email:

Gods 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,
O, Tidings of reason and fact, reason and fact,
Glad tidings of reason and fact.

Our current Christmas Customs come from Persia and from Greece,
From solstice celebrations of the ancient Middle East.
This whole darn Christmas spiel is just another pagan feast,
O, Tidings of reason and fact, reason and fact,
Glad tidings of reason and fact.

I thought it was great, so I wanted to look it up online and see if I could find a source to attribute it to on this blog. I find many and conflicting sources, but I also discover that the version she was emailed had been bowdlerized! There's a third verse in the versions I find online:

There was no star of Bethlehem, there was no angels' song;
There could not have been wise men for the trip would take too long.
The stories in the Bible are historically wrong,
O, Tidings of reason and fact, reason and fact,
Glad tidings of reason and fact!

So apparently her circle of friends are passing around the skeptical/agnostic version of the song rather than all-out-atheist-denial version.

Wouldn't want to offend.