The devil chafes and rages as a fierce enemy against us with all his power and might...

No one can believe how the devil opposes and resists these prayers.  He cannot allow anyone to teach or to believe rightly.  It hurts him beyond measure to have his lies and abominations exposed, which have been honored under the most fancy, sham uses of the divine name.  It hurts him when he himself is disgraced, is driven out of the heart, and has to let a breach be made in his kingdom.  Therefore, he chafes and rages as a fierce enemy with all his power and might.  He marshals all his subjects and, in addition, enlists the world and our own flesh as his allies.  For our flesh is in itself lazy and inclined to evil, even though we have accepted and believe God's Word.  The world, however, is perverse and wicked.  So he provokes the world against us, fans and stirs the fire, so that he may hinder and drive us back, cause us to fall, and again bring us under his power.  Such is all his will, and mind, and thought.  He strives for this day and night and never rests a moment.  He uses all arts, wiles, ways, and means that he can invent.

~BOC, LC, III, 62-64