It is important to realize that nowhere in this book are we given reason to believe that Job’s depression, in and of itself, is ever viewed by the Lord as being his own “fault.” On the contrary, in view of the clear mandate for unlimited harassment (short of death) given to Satan in the Prologue, we are constrained to see Job’s psychic trauma as part and parcel with his other trials, just one more of the Devil’s assaults upon his faith. In fact the message that begins to unfold in Chapter 3 is that depression in a believer, far from being unforgivable, is one of the things that the Lord is most ready and eager to forgive. It may even be something that does not call for forgiveness at all, and far from being a sign of loss of faith it may actually demonstrate the presence of the sort of genuine and deeply searching faith that God always honors.
— Mike Mason, The Gospel According to Job, p. 59-60