December 25-January 5
The celebration of Christ’s incarnation at Christmas is one of the two poles of the Christian year. The wonderful mystery of God’s dwelling among us in the fullness of humanity, as Emmanuel, foretold by the prophets and born of Mary, provides the material of the feast. Christmas is much more then than simply the celebration of Jesus’ birth…the task of the Christmas liturgy is to recall us, amid all the joyful customs and celebrations of Christmas, to this central truth of the Word made flesh for our salvation.
It is, of course, Christ’s nativity that has provided the occasion for this festival of the incarnation, since the end of the third century. The Christmas crib and the nativity play can both be said to descend from the tableau of Christ’s birth that Francis of Assisi arranged when he celebrated Christmas at Greccio in 1223. Christmas carols are a medieval tradition, which has been notably developed from the end of the nineteenth century. The Festival of Lessons and Carols is itself an influential English creation of the late nineteenth century, made widespread by the choir of King’s College, Cambridge, in the first half of the twentieth.
The Christmas season is often celebrated for twelve days, ending with the Epiphany (which takes place on January 6th).
-Times and Seasons, The Church of England