Merry X'mas?

It's another Christmas, which means a year has come to it's end. My family is not christian, so Christmas is just a public holiday for us. Except my sister who is a sincere Christian. Heard a story about Christmas from my sister when i asked her how her church celebrating Christmas this year. My sister said this issue still under debate, so i'm just telling this as a rumour. Didn't mean to insult anyone.

Do you realise some greetings nowadays or properly you yourself also using "Merry X'mas" instead of "Merry Christmas" ? Most people will think tat's just a short form just like me. But it's X-mas, not really sound like Christmas isn't it?

Well actually, the 'X' has the same meaning as in mathematics. An unknown. They are telling that Christmas is not Christ's birthday! Even the Bible never mentioned about His birth date. So some philosophers suggested that Christmas actually is not Christ's birthday. But due to some incidents/mistakes (Not sure about this part, forgive me if any wrong information), 25th of December is treat as Christ's birthday and being celebrated by Christian for centuries until now.

Furthermore, Christmas nowadays is also celebrated even by none Christian. Many culture of Christmas formed also seem to be not related to christianity. Santa Clause, Christmas tree, etc etc.. So, they remove the word 'Christ' and replace with an unknown 'X' to compromise the Christmas that had been commercialize in modern societies...

Next time, when u writing greetings to people, think again... 'Merry Christmas' or 'Merry X'mas' ?