David and Job often complained that God had left them, had become their enemy, regarded not their prayers, and took no heed to deliver them. And yet it is impossible that God shall either leave his chosen, or that he shall despise the humble petitions of such as do incall his support. But such complaints are the voices of the flesh, wherewith God is not offended so as to reject his elect, but pardons them among their innumerable infirmities and sins.
And therefore, dearly beloved, despair you not, albeit the flesh sometimes bursts out in heavy complaints, as it were, against God. You are not more perfect than were David and Job; and you cannot be so perfect as Christ himself was, who, upon the cross, cried, “My God, my God, why hast thou forsaken me?” (Matt. 27:46).
Consider, dear mother, how lamentable and horrible were those words to the only Son of God. And David, in the 88th psalm (which, for the better understanding, I desire you to read) complains upon God, that night and day he had cried, and yet he was not delivered; “But,” says he, “my soul is filled with dolour; I am as a man without strength. I am like unto those that are gone down into the pit, of whom thou hast no more mind; like unto those that are cut off by thy hand. Thou hast put me in a deep dungeon. All thy wrath lieth upon me. Why leavest thou me, Lord? Why hidest thou thy face so far from me? Thou hast removed all my friends from me. Thou hast made me odious unto them” (Ps. 88:3-8).
And thus he ends his psalm and complaint, without mention of any comfort received. And Job, in diverse places of his book, makes even the like complaints; sometimes saying that God was his enemy, and had set him, as it were, a mark to shoot at; and, therefore, that his soul desires actual destruction (cf. Job 16:13).
John Knox, An Exposition of the Sixth Psalm