For our other faults and passions may be said to be simpler and of but one form: but this takes many forms and shapes, and changes about and assails the man who stands up against it from every quarter, and assaults its conqueror on all sides. For it tries to injure the soldier of Christ in his dress, in his manner, his walk, his voice, his work, his vigils, his fasts, his prayers, when he withdraws, when he reads, in his knowledge, his silence, his obedience, his humility, his patience; and like some most dangerous rock hidden by surging waves, it causes an unforeseen and miserable shipwreck to those who are sailing with a fair breeze, while they are not on the lookout for it or guarding against it.
Reproduced in full. Translation: Nicene and Post-Nicene Fathers, series 2, vol. 11 (Schaff and Wace, 1894), public domain (Public domain).