Celebrating the birth of Christ is a good thing. I know some of our puritan brothers from the past didn't do it, but I believe it provides a great oportunity to say to the world: Jesus the Messiah has come and He is coming again (soon)! People will dispute the date, but Edershiem in The LIfe and Times of Jesus the Messiah
has a great explanation of this; I believe silencing the critics. Another thing some Christians rail about is the so called pagan origins of Christmas. Certainly that may be valid, but does anyone think of that today when putting up trees, etc. and after all isn't that what the Gospel is all about: making things new in Christ. My best advice... celebrate Christ at Christmas; exchange gifts in memory of the greatest gift Jesus Christ, put up a Christmas trees remembering the evergreen as a symbol of eternal life in Christ Jesus, and light-up candles or Christmas lights (or down here in New Mexico- luminarios)because the Light of Christ has come into the world, and above all prepare your hearts for His coming again.