St. John of the Cross' Dark Night of the Soul

He strips their faculties, affections and feelings, both spiritual and sensual, both outward and inward, leaving the understanding dark, the will dry, the memory empty and the affections in the deepest affliction, bitterness and constraint, taking from the soul the pleasure and experience of spiritual blessings which it had aforetime, in order to make of this privation one of the principles which are requisite in the spirit so that there may be introduced into it and united with it the spiritual form of the spirit, which the union of love.