He was born, allowed Himself to be killed by sinners that sinners need not perish, and rose again from the dead to fulfill the prophesy/promise of Grace. Some of these "essays" are useless diversions that do not add to the message/truth.
trebb:
Because the Incarnation is a fundamental Doctrine of the Faith of the Catholic Church and the Orthodox Church has well. The Liturgical calendar of the Catholic Church orders time and space in accordance with the Life of Christ and the worship cycle of the Liturgical calendar reflects on all the central fundamental doctrines about Christ. Advent is the season of preparation for the coming of CHrist, a reflection on his 1st coming, a reflection on his presence among us here and now, Emmanuel [God is with us] and preparation for his 2nd coming. The Christmas season is celebration that Christ really did become incarnate of he Virgin Mary and became Man [as the Nicene Creed defines]. Thus, celebrating his birth is constant reminder to people of faith and a witness to the secular world and non-Christians that the Word became Flesh and dwelt among us.
So this message does add to the Truth, it just does not fit your particular little non-Catholic groups views of what is he truth or what is relevant. Obviously, it was relevant to countless Church Fathers going back to the 2nd and early 3rd century.