Maybe most people will already know this, Christmas is a pagan holiday if you follow it, greet in it, part take in it then you could be committing sin especially if you follow any of the abrahamic religions.
E.g from Old testament Jeremiah 10:1-25
Hear the word that the Lord speaks to you, O house of Israel. Thus says the Lord: “Learn not the way of the nations, nor be dismayed at the signs of the heavens because the nations are dismayed at them, for the customs of the peoples are vanity. A tree from the forest is cut down and worked with an axe by the hands of a craftsman. They decorate it with silver and gold; they fasten it with hammer and nails so that it cannot move. Their idols are like scarecrows in a cucumber field, and they cannot speak; they have to be carried, for they cannot walk. Do not be afraid of them, for they cannot do evil, neither is it in them to do good
I'm not a religious scholar but I would ask for those of you who are religious to do your own research before you pass something off as being minor or a nothing. Just because a mass of people follow something does not make it right.