From Denise Levertov, a late Jewish convert to Catholicism, a poem, On the Mystery of the Incarnation:
It's when we face for a moment the worst our kind can do, and shudder to know the taint in our own selves, that awe cracks the mind's shell and enters the heart: not to a flower, not to a dolphin, to no innocent form but to this creature vainly sure it and no other is god-like, God (out of compassion for our ugly failure to evolve) entrusts, as guest, as brother, the Word.
Have you ever – in your wildest imagination – dared to say, “God entrusts His Son to us”? He entrusts to man – “to this creature vainly sure/it and no other is god-like” – to us He entrusts His infant son. What if Advent were not a joyful season of anticipation and preparation for the arrival of the Christ Child? What if Advent were instead a trial, a five-week test to determine whether or not we – vain creatures that we are – were worthy of being entrusted with the care of God's infant Son? Assuming that we want this grave responsibility and the eternal reward of a job well-done; and assuming that we are confident enough in our holiness, can we look back on the last month or so and say that we have earned the Father's trust?
As a race, as made-beings, created in love to resemble both the image and likeness of our Creator, can we stand face-to-face with God and say with all humility, “Yes, Lord, we are worthy of your trust”? No, never. And herein lies the devastating truth of the Incarnation. God the Father entrusts His only begotten Son to us, knowing that we are not now, never have been, nor ever will be worthy of His trust or His love. Yet, yet. He loves us and trusts nonetheless. The Word, the Son takes on human flesh through the virginal womb of Mary despite our ancient history of violence, disobedience, and our perverse love affair with death. His salvation has come; his justice is revealed. And, despite our unworthiness, we are the emissaries of both.