Another major mistake of popular Christianity is concerning the birthday of Jesus. The shepherds were sleeping in the fields with their flocks at the time of Christ's birth (Luke 2:8); they would not have been doing this at Christmas time, during the winter. Christ lived for 33.5 years and then died at the feast of Passover, which is at Easter time. He must therefore have been born six months the other side of Easter - i.e. around September/October.
December 25 was originally the date of a pagan feast in pre-Christian Europe. The Acts of the Apostles records how the true Christians were badly persecuted by the pagans because of their beliefs. Time and again the apostles warned that because of this, some Christians would adopt pagan beliefs, to enable them to make their religion more palatable to the pagans around them (e.g. Acts 20:30; 1 John 2:18; 2 Thess. 2:3; 2 Peter 2:1-3). The adoption of December 25 as a Christian festival is a prime example of this. Christmas trees, mistletoe etc. can all be traced back to pagan rites practiced on December 25.
It follows from this that true Christians should not celebrate the birth of Christ on December 25. In practice, true believers will make use of most public holidays, e.g. Christmas, to fellowship together wherever possible.