Eliphaz drives home the spear and even twists it:
“Behold, God puts no trust in his holy ones, and the heavens are not pure in his sight; how much less one who is abominable and corrupt, a man who drinks injustice like water?... the wicked man writhes in pain all his days” (15:15-16,20).
Eliphaz misquotes Scripture! I have seen many a wicked man who has thrived quite well all his life; any “reward” he receives likely comes when he arrives freshly in hell. And of course, many a saint suffers throughout life, only to receive all the blessings of heaven after death.
In Chapter 16, Job responds by suggesting his friends are “miserable comforters” (16:2). Job reiterates that despite the brutal punishment he is enduring from God (so he thinks), he is innocent and his prayer to God is pure (16:17). Then he says something stunning:
“Even now, behold, my witness is in heaven, and he who testifies for me is on high…that he would argue the case of a man with God, as a son of man does with his neighbor” (16:19, 21).
Job is not asking who will plead his case before God. He knows that God is pleading Job’s case before God! Isn’t this a contradiction? With no knowledge whatsoever of the Messiah to come, Job foresees that God can be more than one person and still be God!
Job’s accusers can say anything they want – Job knows their petty explanations expose gross stupidity. He concludes:
“Yet the righteous holds to his way, and he who has clean hands grows stronger and stronger” (17:9).
Job refuses to give up because he knows that there is one “like a son of man” (16:21) who pleads his case directly before God.
Job is turning the Cycle upside down, in a good way. Are his protestations to God temptation or outright disobedience? Are the responses of Job’s friends unity with God, patiently telling it like it is to a lost sinner?
No! At first it only seems that way when reading verse to verse. But when an entire section is taken as a whole, it becomes clear that Job is in perfect unity with God, prepared to endure even to death in the blessed assurance that God loves him! And it is Eliphaz and company who do what too many of us do when we see a friend in trouble: quote Scripture out of context in warning, judgment, and disunity. It is Job, whose every word is in perfect unity with God!
Who will plead your case before God? It is Jesus Christ, the Son of Man, if you accept him in perfect unity. Remember, Jesus pleads before God for you, but there is even more in the New Testament that Job cannot know:
“Likewise the Spirit helps us in our weakness. For we do not know what to pray for as we ought, but the Spirit himself intercedes for us with groanings too deep for words. And he who searches hearts knows what is the mind of the Spirit, because the Spirit intercedes for the saints according to the will of God.”
Remember Job 16-17 when someone asks you about the Trinity!
 The Holy Bible: English Standard Version. (2016). (Ro 8:26–27). Wheaton: Standard Bible Society.