In Southern California in the 1960s there was a rising tendency by holiday advertisers and Christmas tree lot merchants to use a heathen abbreviation when referring to the celebration of Christmas. It had become popular and acceptable to use the paganistic devil-worshipping term, Xmas, probably to save space, and ink, paint, and paper. Roman Catholics in particular were offended by the removal of Christ's name from the holiday, and thus began a movement to "Keep Christ in Christmas."
The movement was talked about at church and you could get a bumper sticker that actually said, "Keep Christ in Christmas." I don't think our family put one on our car because we apparently weren't the bumper sticker type, but just about every other car in our church parking lot had one. Whether the campaign was successful or not, I don't really know. Seriously, the folks who used "Xmas" were painted as ignorant apostate yokels who preyed like ravenous lions on devout Christian lambs and cared only for their own filthy lucre.
Decades later, as I dug deep into our Carpatho-Rusyn family history and learned to read the Cyrillic alphabet, I discovered that in the Eastern Rite Christian cultures, what appeared to us as the letter "X," is the Greek letter Chi which standing alone can symbolize our Savior, Jesus Christ. The light bulb went on as I realized why the Roman Catholic Church club for teenagers was called Chi Rho. The letters Chi and Rho together--XP--also symbolize Christ and is often visible in icon paintings.
Curiously, the trend of decades before to seemingly drop Christ's name from Christmas could be understood on two levels. Were seemingly lazy merchants attracted to the ease of using "X," or, was there an understanding that the use of "X" was as valid as using the name of Christ? Well, I think we would all agree that the commercially used term Xmas was done for ease of use. Much simpler to spray paint Xmas on your scrap piece of plyboard in front of your tree display in the gas station parking lot, than to try to spray the 9-letter C-h-r-i-s-t-m-a-s.
Merchants and the folks up in arms about Xmas may not have known the truth, and Xmas has not lost its offensive air to Christians. When I drive by an Xmas tree lot though, I smile and think, yeah, that works.