My friends quite often have this question following immediately after wishing me a "Merry Christmas". Now there are so many ways I can answer this question. But I'll address it in the following two points.
1. Yes I do believe in Christmas, the whole world celebrates it on the 25th of December of every year and the evidence is quite clear that Christmas takes place on that date.
Do I believe that Jesus was born on that date? No absolutely not. The evidence of His birthday would suggest a different date. But I have never spent any huge amount of time to pinpoint the exact time, because nowhere in the Bible does it teach to celebrate His birth. He makes it quite clear that the only holy/holi-days we should commemorate are the weekly Sabbaths and communion dates which haven't been allocated any special dates to "...do this in remembrance of me" 1 Corinthians 11:24.
I actually appreciate that the world takes time to be open to hear/see and learn of the story of the birth of Christ. It could be the only part of the Bible that some people ever get exposed to, but even that's a great start for those who don't know Him as the greatest gift that the Father gave to humankind. And as a Christian I would take full advantage of this time to speak of Jesus Christ that would otherwise fall on deaf ears at any other time of the year.
2. Why would I celebrate that day if I don't believe that Jesus was born on that date? Because the secular world recognises it as a holiday, and I get to spend time with family and friends because they have time off from work and school etc. (But even them working on Christmas days are becoming more frequent). My family and friends who observe the Sabbath like me get to do this on a weekly basis. We get together, worship Christ, hear from his word and have a great time together. If you could experience what happens on Christmas day more often than just that one time in the year? Wouldn't you grab the opportunity? Family time is divine. And there is never a time where I compromise my faith by spending time with family and friends.
I believe the awesomeness of Christmas is not the receiving of gifts, rather the "giving" of gifts!. A huge reminder to all of us that "freely we have received, freely give" - Matt 10:8. Starting with your family and friends is easy. But why not take time out to learn about those who dread Christmas because they have no family left, or worse yet have no friends? Why not take time out to search these people out and give? And there are plenty of local charities where you can donate funds, toys, food etc in times like these.
Do I take full advantage of this as well? Absolutely, my Son is challenged to consider other children his age who are not as privileged and to give away without receiving. If you're a parent, you would be wise to do the same, compassion is a character trait too scarce in society.
Do you believe in Christmas?
Shalom,
Dave