Every time Christmas rolls around the topic of whether Christmas is a pagan holiday and if Christians should even celebrate it comes up in some circles.  Below are answers from several pastors and theologians:

• John Piper tells us to sanctify the day and celebrate Jesus birth even if the date was originally related to a pagan holiday
• RC Sproul answers that December 25th was a pagan holiday, but he believes that God is pleased when we celebrate Christmas
• The Christian Research Institute (CRI) has a reasonably detailed statement about Christmas including the use of Christmas trees and the tradition of Santa Claus.  Elliott Miller, from CRI, concludes that we should be guided by Romans 14:5-6, 10 where we can choose to not observe it if we wish, but shouldn’t judge someone who does celebrate Christmas
• John Ankerberg’s staff believes that it’s good to celebrate Christmas and we can celebrate any day as long as our conscience permits.  Despite the history of the date, it is the current meaning of the day and symbols that matter as we use them to glorify God
• RC Sproul weighs in with the statement that ‘he can’t think of anything more pleasing to Christ than celebrating his birthday every year’.
• The Biblical Archeology Review provides a history of how December 25th became the day we celebrate Jesus’ birth
• For what it’s worth, the History Channel provides its view on the history of December 25th and its relationship to Christmas concluding that Christians chose the date to compete with a pagan festival and ‘baptized’ other pagan traditions like the tree in order to replace them as Christian symbols.  On the topic Christmas trees, it also has an extensive article on their history including references to Luther and the Puritans

The consensus from the articles is 1) December 25th was a Roman pagan feast day called Sol Invictus (the birth of the unconquered sun) 2) No one knew Jesus true birthday, so Christians chose to replace the existing pagan day of celebration with a celebration of Jesus’ birth 3) though the date is pagan in origin, no pagan ideas continue today in our celebration 4) Romans 14 provides us the freedom to celebrate on a date of our own choosing if our conscience is clear about it