A man pushed to the absolute edge of human endurance faces a terrible conflict. He is torn between the certainty of his own innocence and the crushing weight of unexplained suffering, a battle that ultimately drives him to complete despair and a profound rejection of life itself. The primary approach among commentators is that Job makes a clear, unwavering declaration of his innocence. He testifies that he is an upright man, entirely free from sin, and knows with absolute certainty that he has done no wrong [רש"י, מצודת דוד, רמב"ן]. Alternatively, this opening thought is not about justice, but about physical ruin. In this view, Job is describing how his body is completely wasting away and fading into nothingness from the sheer intensity of his pain [רלב"ג].
Out of this agony emerges a deep confusion about his own soul. On a physical and emotional level, his suffering is so overwhelming that he can find no rest [רש"י]. He feels as though he is already dead, no longer recognizing the life force within himself or the energy in his own limbs [מצודת דוד, רלב"ג]. Intellectually, this confusion can be understood as a cry of astonishment. He wonders how anyone could claim he does not know his own soul, for he knows himself intimately and is certain there is no evil within him [ביאור שטיינזלץ, אבן עזרא]. Yet, the pain also plants seeds of deep self doubt. Job wonders if he does not truly know himself and might actually be wicked, just as God's harsh judgment seems to imply [מלבי"ם]. He even considers that his good nature might not be the result of his own free will, but simply a trait ingrained in him from creation, meaning he deserves no reward for his righteousness [מלבי"ם].
On a deeper level, Job admits his complete inability to grasp the spiritual secrets of human existence. He cannot understand the foundations of the soul, the complex bond between the soul and the body, or why God would decree such terrible tragedies upon it [רמב"ן, תקות אנוש]. Taking this mystery further, some suggest Job is grappling with the concept of reincarnation. While he knows he has lived a pure life in his current body, he does not know the history of his soul. He fears that his soul may have sinned in a previous lifetime, leaving his currently innocent body to suffer the punishment for past wrongs [חומת אנך, אלשיך].
Consumed by helplessness, immense agony, and a total lack of understanding, Job reaches a tragic conclusion. He completely rejects his own existence, preferring death over a life of disgrace where a righteous person is forced to view himself as wicked, or a life completely devoid of free will [מלבי"ם]. He longs for the moment his soul will separate from his body and return to its divine source [רמב"ן, תקות אנוש]. Ultimately, he is even willing for his soul to face judgment alone for any hidden sins it may carry, so long as his innocent, broken body no longer has to suffer [אלשיך].