Of the major Christian festivals, Christmas is the most recent in origin. The name, a contraction of the term “Christ's mass,” did not come into use until the Middle Ages. In the early centuries, Christians were much more likely to celebrate the day of a person's death than the person's birthday. Very early in its history the church had an annual observance of the death of Christ and also honored many of the early martyrs on the day of their death. Before the fourth century, churches in the East—Egypt, Asia Minor, and Antioch—observed Epiphany, the manifestation of God to the world, celebrating Christ's baptism, His birth, and the visit of the Magi.
In the early part of the fourth century, Christians in Rome began to celebrate the birth of Christ. The practice spread widely and rapidly, so that most parts of the Christian world observed the new festival by the end of the century. In the fourth century, the controversy over the nature of Christ, whether He was truly God or a created being, led to an increased emphasis on the doctrine of the incarnation, the affirmation that “the Word was made flesh” (John 1:14). It is likely that the urgency to proclaim the incarnation was an important factor in the spread of the celebration of Christmas.
No evidence remains about the exact date of the birth of Christ. The December 25 date was chosen as much for practical reasons as for theological ones. Throughout the Roman Empire, various festivals were held in conjunction with the winter solstice. In Rome, the Feast of the Unconquerable Sun celebrated the beginning of the return of the sun. When Christianity became the religion of the Empire, the church either had to suppress the festivals or transform them. The winter solstice seemed an appropriate time to celebrate Christ's birth. Thus, the festival of the sun became a festival of the Son, the Light of the world. See Church Year.
Fred A. Grissom