Job, who is afflicted by The Accuser, spends most of the book shuttling between anger and faith. He remains steadfast, though he does not shy away from expressing his displeasure at the injustices heaped upon him.
His friends, who express all the typically pious nonsense you still hear today from Christians trying to be helpful, are of no help:
- You must have done something bad, or else this wouldn't have happened
- God has a plan for your life.
- You need to repent.
All of their babbling misses the point, which is that suffering is inevitable, anger toward God is perfectly reasonable (He can take it), and that - FINALLY - the purposes of God are ultimately mysterious and behind our comprehension.
God reveals Himself to Job toward the end of the book, and delivers the longest divine monologue in the Scriptures - the most God has to say about His own nature anywhere in the Bible. And it's quite the speech: "Gird up your loins like a man, and face me." (Or, as I would have rendered it: Put on your BIG BOY panties, Job - things are getting real up in here.)
One way of looking at God's EPIC rebuke of Job might be that his reaction was blasphemous and he needed to be punished or corrected. But I find this a very immature and incomplete reading of the text, especially considering Job's ultimate vindication.
In my view, the better way of understanding this account is to realize that it is through the midst of Job's own dealing with his anger - honestly - with God, that he finally has a Theophanic (God Revealing) experience.
Job reveals his innermost self to God, and God responds by revealing Himself to Job.
You, too, can come before The Lord in your anger, or fear, or despair. You cannot hide from the almighty, whether you fly up to heaven or make your bed in hell. Only by offering your anger, yourself, to God will you ever be able to let go of it.
Your question has evolved to include "and let him know it."
Do not forget that God ALREADY KNOWS. Expressing your anger at God is not about informing the All-knowing Master of the Universe of something. It is, rather, about you coming to grips with your own anger in the presence of the Lord.