For years, I've said Merry Xmas, to the ire of many Christians in my life.
This year, I present: https://en.wikipedia.org/wiki/Xmas
which explains how Χριστός (X) was used centuries before Christ. So while I often hear how I'm part of a conspiracy to take the Christ out of Christmas, I am more aware and respectful of the original intent.
In fact, X was initially kris (sounds like ks if you're Greek), so I propose I'm the leading authority on the matter on this.