The X is there to cut out the word Christ. Some also use it as Xtains.
I am not a Christian who believes in Christmas as the celebration of the birth date of Jesus. It is pagan in origin But that is another matter.
The Use of the x is Xtian is very offensive, It shows that the people who invented this tradition did not want to right the world Christ because it was somehow offense to them to even mention the word Christ.
Is Xmas really another matter, or rather, the heart of the matter ?
Could you picture Jesus dressed up in a Santa suit ? [ Santa being the god of Christmas ]
How did the apostles celebrate the birthday of Jesus? The answer is that they didn't.
Yes, Christmas is non-biblical in origin and always will be.
Jesus taught that worship should be based on truth - John 4 vs 23,24
Christmas is Not religious truth, and smacks of falsehood - flying raindeer - aka Christmas fairy tale in order to play Babes in Toyland.
The nativity scene or story is a good example of how man has handed down false teachings.
Such as: the un-numbered magi being at the manger when they never there.
Would Jesus or the apostles give Christian names to a non-scriptural celebration ?
How many evergreen trees are sacrificed to Santa each year ?
Christmas balls representing the SUN, and Not The Son.
So, isn't Christmas largely a manufactured holiday pointing to its origin in a non-biblical past ?