George MacDonald, “The Voice of Job”:

In the confusion of Job’s thoughts — how could they be other than confused, in the presence of the awful contradiction of two such facts staring each other in the face, that God was just, yet punishing a righteous man as if he were wicked? — while he was not yet able to generate, or to receive the thought, that approving love itself might be inflicting or allowing the torture — that such suffering as his was granted only to a righteous man, that he might be made perfect — I can well imagine that at times, as the one moment he doubted God’s righteousness, and the next cried aloud, ‘Though he slay me, yet will I trust in him,’ there must in the chaos have mingled some element of doubt as to the existence of God. Let not such doubt be supposed a yet further stage in unbelief. To deny the existence of God may, paradoxical as the statement will at first seem to some, involve less unbelief than the smallest yielding to doubt of his goodness. I say yielding; for a man may be haunted with doubts, and only grow thereby in faith. Doubts are the messengers of the Living One to rouse the honest. They are the first knock at our door of things that are not yet, but have to be, understood; and theirs in general is the inhospitable reception of angels that do not come in their own likeness. Doubt must precede every deeper assurance; for uncertainties are what we first see when we look into a region hitherto unknown, unexplored, unannexed. In all Job’s begging and longing to see God, then, may well be supposed to mingle the mighty desire to be assured of God’s being. To acknowledge is not to be sure of God.