Actually, birthdays are a western custom. In the East, the patron namesake Saint is celebrated. Personal birthdays are considered vanity. But for some reason the Church decided to celebrate a date common to the birth of pagan gods. It wasn't a random choice.
Of course Christians should be thinking about Christ all the time, but I think reminders like Holy days are still good things. History has proved that we need all the reminding we can get.
So you think it's something we determine? Not God?
Yes, Protestants have some traditions, but one difference from the formal ones that are dogma is that they are not commanded of us by any higher earthly authority and our salvation has nothing to do with complying with them
Like Trinity?
Latin and Orthodox Churches almost always involve a tradition we believe is in violation of scripture, or is based on an interpretation of scripture with which we strongly disagree
Where do you find in scriptures such beliefs as "sola scirptura" or co-equal, co-eternal Trinity?
So you think it's something we determine? Not God?
No, I think it's from God. It matches what we see in scripture. Christ Himself said "Do this in remembrance of me." Therefore, I would think He would approve of any time or occasion when He is remembered. Forget all the commercialization baloney, reflecting on and remembering the story of His birth has to be a Godly thing. Linus had it right when he said "That's what Christmas is all about, Charlie Brown." :)
FK: Yes, Protestants have some traditions, but one difference from the formal ones that are dogma is that they are not commanded of us by any higher earthly authority and our salvation has nothing to do with complying with them
Like Trinity?
I don't at all consider the Trinity to be extra-scriptural Tradition. The totality of scripture contains the whole idea of the Trinity. I think I have posted this website before, but just in case see: Trinity in the Scriptures.
FK: Latin and Orthodox Churches almost always involve a tradition we believe is in violation of scripture, or is based on an interpretation of scripture with which we strongly disagree
Where do you find in scriptures such beliefs as "sola scirptura" or co-equal, co-eternal Trinity?
The website handles the Trinity stuff, and for Sola Scriptura here are some examples in support:
We also have Jesus' example of handling every temptation of satan with scripture only.