One of the essays included is by Alfred Delp (1907-1945) a German priest martyred under Hitler. Here's what he says about John the Baptist as a messenger of Advent:
Woe to an age when the voices of those who cry in the wilderness have fallen silent, outshouted by the noise of the day or outlawed or swallowed up in the intoxication of progress, or growing smothered and fainter for fear and cowardice. The devastation will soon be so terrifying and universal that the word "wildernesss" will again strike our hearts and minds. I think we know that.
But still there are no crying voices to raise their plaint and accusation. Not for an hour can life dispense with these John-the-Baptist characters, these original individuals, stuck by the lightning of mission and vocation. Their heart goes before them, and that is why their eye is so clear-sighted, their judgment so incorruptible. They do not cry for the sake of crying or for the sake of the voice. Or because they begrudge earth's pleasant hours, exiled as they themselves are form the small warm companionships of the foreground. Theirs is the great comfort known only to those who have paced out the inmost and furthermost boundaries of existence.
They cry for blessing and salvation. They summon us to our last chance, while already they feel the ground quaking and the rafters creaking and see the finest of mountains tottering inwardly and see the very stars in heaven hanging in peril. They summon us to the opportunity of warding off, by the greater power of a converted heart, the shifting desert that will pounce upon us and bury us.
Father Delp wrote these words over sixty years ago. How do they apply to us?