1.
[Harv writing letter.]

Dear Agios Nikolaos,
Some idiot today told me that by writing "Xmas," I was "taking the Christ out of Christmas."

2.
But isn't "Xmas" derived from Chi, the first letter of Christ's Greek name, Xristos, and therefore meaning, "Christ's Mass?"  Isn't there, in fact, a long tradition of this usage in religious writing?

3.
Personally, I couldn't give a fig one way or another, as I celebrate the commercial Christmas holiday - a holiday of twenty-four-hour stop-motion animated Yuletide specials and liberal amounts of eggnog. 

4.
It is the holiday of the cranberry chicken nugget sauce, the plastic tree, and the inflatable snow man.  I call it "Cashmas."

It can be abbreviated thusly: "$mas."