From On Conversion (1140) in Bernard of Clairvaux: Selected Works, trans. G.R. Evans (New York: Paulist, 1987).
“‘The Word of God is living and effective,’ Heb 4:12. ‘His voice is a voice of magnificence and power,’ Psalm 28:4… He said, ‘Be converted,’ Psalm 89:3, and the sons of men have been converted. So the conversion of souls is clearly the work of the divine voice, not of any human voice. Even Simon son of John, called and appointed by the Lord to be a fisher of men, will toil in vain all night and catch nothing until he casts his net at the Lord’s word, John 21:15. Then he can catch a vast multitude, John 21:15; Matt 4:19. Would that we, too, might cast our net at this word today and experience what is written, ‘Behold he will give his voice the sound of power,’ Psalm 67:34… I can hope that what I say will be effective only if he makes it so. I must ask him to make this voice of mine a voice of power. I admonish you, therefore, to lift up your heart to hear this inner voice, so that you may strive to hear inwardly what is said to the outward man. For this is the voice of magnificence and power, rolling through the desert, revealing secrets, shaking souls free of sluggishness, Psalm 28:4; Psalm 28:8.
St. Bernard of Clairvaux (1090-1153) was one of the most influential preachers and spiritual writers of the Middle Ages. An important leader in the Cistercian reform, he was abbot at Clairvaux and an important advisor to other church leaders. The sermon On Conversion was preached to a congregation of scholars and students in Paris. More than twenty of those who heard it were moved to enter the religious life, and became professed members of the community at Clairvaux.