Anyway I recently happened across a decent article on exposing the pagan lies about Christmas that come around every year about this time.
Christmas and its Christian Origins from "Fair Minded Notions" blog.
Some of the many good links at the end don't work so well so I had to do some investigation and googling to find the articles they linked to.
This last section:
Should be these links:
The Pagan Origins of Christmas?
Is Christmas Pagan? (repost from FreeRepublic)
The True Origins of the Christmas Tree (This was the first link that didn't work as formatted)
On Various Christmas Symbols
The Stag (Deer) (this one incorrectly linked to the Lion section of the page)
on the Mithras section:
The Myth of the Pagan Christmas; or Why Stephen Fry was Wrong on Mythmas
Refuting Mithras Myth Parallelism To Christianity
Debunking the Jesus-Mithra Connection
Exploding the Mithras Myth
Christmas Date Does NOT Have Pagan Origins (This one was wrongly formatted so I found the original)
Calculating Christmas(This one was also wrongly formatted)
Did Christianity Steal the Date of Pagan Winter Solstice Celebrations?
Did Christianity Steal the Date of Sol Invictus?
MYTH: Too cold for shepherds to Tend Flocks in December
Unbelievable? 25 Dec 2010 - The Unbelievable? "Christmas Cracker
Should We Have A Christmas Tree?
Christmas Trees Are Not Pagan!
Jeremiah 10 and Christmas Trees
Are Christmas Trees Idolatrous?
Is Christmas Really A Pagan Holiday?
I also found a couple good articles by Rev. Dr. Richard P. Bucher, LCMS
Jeremiah 10 and the 'pagan' Christmas Tree
Christmas is NOT Pagan part 1
Christmas is NOT pagan part 2
Christmas is NOT Pagan part 3
Christmas is NOT Pagan part 4
O Christmas Tree: The Origin and Meaning of the Christmas Tree
The Origin of Santa Claus and the Christian Response to Him
What is the Season of Advent?
The Magi / Wise Men FAQ
In addition, Issues, Etc. dealt with the Christ-Myth theory recently on their radio program:
3. The Christ Myth Theory – Pr. Joseph Abrahamson, 12/19/14
Christ Myth Theory [Jesus is a copy-cat]