Hi @jancharlest thanks for dropping by here on my page. Glad I still saved this post so that I could reply, though it's late.
Happy New Year by the way. Hope you enjoyed the celebrations.
So, you were asking what was the reason. I'm an Iglesia ni Cristo and although Im a convert, when I was younger, I loved reading the bible. And so at a very early age, I already understood that Dec. 25 wasn't really written anywhere in the Bible. Perhaps this link could help you better understand what I am trying to say Check it out.
Hey thanks again for dropping by. Have a good day.