Christmastide is the season that provokes the most spiritual reflection, accompanied by abundant joy. Amongst feasts in the liturgical calendar, over the centuries Christmas has either enjoyed a most favored festive status or been nearly ignored.

Two of the four Gospel authors, Mark and John, omit any mention of the birth of Jesus. Matthew’s account is the abridged version. It is Luke’s full-figured account of the pilgrimage to Bethlehem, the lowly manger scene, the Angels, shepherds, the guiding star, the gifts of the Magi, all of which we never tire, reading a million times over.

After all, Christmas celebrating the birth of Jesus is a simple fait accompli. Preceding Christmas by an infinite distance is the most profound event, the foundational mystery of the Christian faith, the a priori Incarnation of the Son of God.

In the Church calendar at ground level, the Incarnation is manifest in the Annunciation to Mary -- the perfection of the Word according to the opening of John’s Gospel -- celebrated in late March, proximo to the vernal equinox. Luke devotes the most poetic ink to the Annunciation, with his Magnificat (Luke1:46-55 KJV), the Song of Mary, settings of which are sung, or said every day within the Liturgy of the Hours, be it Roman Catholic and Lutheran vespers, Anglican evensong, or Eastern Rite morning service.

The Incarnation is necessary, according to Thomas Aquinas in the 13th century, as the most elegant and graceful solution in bestowing the option for redemption and salvation upon humankind. A millennium earlier Tertullian declared that God becoming Man was shameful, absurd, and impossible; thus certain.

I suppose students of philosophical theology might consider Christmas a posteriori, while the Incarnation a priori. Yet Christmas is also necessary to transport the theological abstraction of the Incarnation, albeit true and real enough, into the realm of human experience as God amongst us. None of this is remarkable for mature Christians, accustomed to spiritual self-examination, and sober appraisal, during Advent. Yet there are fewer and fewer Christians, mature or otherwise, willing to submit to such celebral toil.

It is said Luke was a physician, so fitting as a healer with words. It is Luke’s narrative of the Nativity, taking on the coloratura of folklore rather than strictly a sacred chronicle, a tale of a humble hardscrabble family inspiring awe and wonder. Christmas reveals the life of the Son of Man, compressed into the ensuing four months of the Church calendar, leading to the death of God on the Cross, and His resurrection.

Again Tertullian’s words offer an unlikely opening to faith: “The Son of God died; it is by all means to be believed, because it is absurd. And He was buried and rose again; the fact is certain, because it is impossible” (Tertullian, On the Flesh of Christ 5.4).

Tertullian identifies the three core beliefs in the Christian mind: Incarnation, Death, and Resurrection. Nothing else matters, all three must be taken together.

Arguably it is the Incarnation that matters most, where “the Word became flesh and dwelt amongst us”. (John 1:14). On one level it is God’s do-over, since His first human creation Adam, “Lay Ybounden”. On another plane, the Life of Jesus, set out in all four of the Gospels, is a more intellectually approachable record that God is, has been, and always will be with us.

The phrase “mature Christians” is a rank-order label, used in bible study circles to identify the most literate, and learned daily readers who navigate the New and the Old Testaments with ease. Yet ‘mature Christian” is a misnomer. No one “matures” beyond the astonishing truth of the Incarnation. We are all children, seeing the night sky dome for the first time, believing in the moment, yet utterly unable to comprehend any of it.

Barton Swaim, writing a book review in the Wall Street Journal on Jay Parini’s Jesus: The Face of God takes a well-placed swipe at “mature” intellectuals, somehow embarrassed by the demands of faith, unwilling to enter Tertullian’s glorious paradoxical labyrinth. Says Swaim:

“It's the same with all attempts to make religion palatable to the learned. Rather than accepting its authority or ditching it altogether, the urge is to weaken its demands and make its doctrines vague or optional. The result is usually an agreeable but boring philosophy that anyone can adopt and no one would die for.”

Swaim then references Parini’s perspective:

"The Way of Jesus..." Mr. Parini writes, "involves self-denial, a sense of losing oneself in order to find oneself, moving through the inevitable pain of life with good cheer, accepting gracefully the burdens that fall on our shoulders and the tasks that lie before us. This is true discipleship."

Swaim concludes:

“If that's all Jesus came here to tell us, it's hard to see what all the fuss was about.”

Christmas is the best place to embrace the fuss, enter that space, the light of the world, where demands on the human intellect are incontrovertible, yet never resolved. And yes, Christmas is the fruit of the Beginning, but also the beginning of a journey into the holy world of the wholly other.