From Alfred Delp, a German Jesuit priest and philosopher of the German Resistance. He was arrested, sentenced to death and executed by the Nazis in February 1945 (quoted in Bill Wylie Kellermann’s Seasons of Faith and Conscience: Kairos, Confession, Liturgy, 1991):

Advent is a time for rousing. Human beings are shaken to the very depths, so that they may wake up to the truth of themselves. The primary condition for a fruitful and rewarding Advent is renunciation, surrender…A shattering awakening; that is the necessary preliminary. Life only begins when the whole framework is shaken.