Celebrate Christmas because you know the reasons to think the gospel is not real or
Celebrate Christmas because you think it gives you a happily ever after
Celebrate Christmas because of the things about it that you enjoy, what ever.
Avoid the things about Christmas that you loathe, manage it which ever way you like.
I celebrate that I have discovered the books & websites which share the reasons to think that the supernatural tales are not real. Seth Andrews, "The Thinking Atheist" made a great video, "Drawing back the curtain". I think the information Seth shares enriches Christmas. Well it makes a deliciously bitter sweet dialectic.
I love to scoff at Christmas. When Christmas carols come on the radio I enjoy to think of opposite lyrics. Some people get to play the fool and I get to play the wise man, but then they probably think I play the fool and they play the wise man. As Richard Dawkins said in TGD the common man thinks its true, the educated man thinks its false and the ruler thinks its handy. [You can't have a parody if you don't know the original ]
There is a wealth of skeptic freethought surrounding the nativity stories that can be a spur to studying the history of astronomy etc.
Aaron Adair makes good points in his book,"The star of Bethlehem: A skeptical view"
Jonathon M.S. Pearce does a similar thing in,"The Nativity:A critical examination"
I would like to send wide angle Christmas cards that expand peoples vision. The nativity story has Jesus go to Egypt, so I would have a picture of a pyramid with the name Osiris & the 42 negative confessions (1250 BCE), the magi would be Galileo offering the baby a telescope, Leeuwenhoek offering a microscope, Amerigo Vespucci offering a Globe, the star would be comet 67p with Rosetta probe orbiting and Philae Lander on it - reminding of the Philae obelisk with its decree written in both Egyptian hieroglyph & ancient greek , the Rosetta stone with its hieroglyph, demotic & ancient Greek. The angels might be Darwin & Ingersoll. This is the fantastic tale of how science & reason & careful study have gone through every detail in the Bible stories and shown where they are wildly improbable.
I can see that there are bits of religion that people would want to be true - the happy ever after. i find that I have no less security about that, maybe more. I think a loving deity would take everyone to a happily ever after, if there was one but since it looks like there is no supernatural then I look forward to resting in peace. R.I.P looks positively rosy once you have looked into the pit of worst fears. It is possible to see religion as amusing fiction fantasy. ( except for its real life impact )