Remember, that the devil has only one door by which to enter the soul: the will. There are secret or hidden doors. Temptations, discouragement, and unrest are the wares offered by the enemy. Remember this: if the devil makes noise, it is a sign that he is still outside and not yet within. That which must terrify us is his peace and concord within the human soul.
-- Saint Padre Pio of Pietrelcina