One of the ways we can look at the book of Job is as a dialogue between the books of Proverbs and Ecclesiastes. The book of Proverbs says that the fear of the Lord leads to blessing, and foolishness leads to death. If you obey, it will go well with you; if you disobey it will go badly. In Proverbs, Solomon says that the world is fairly predictable, orderly, and it makes sense. However, Solomon answers this wisdom with another aspect of wisdom in Ecclesiastes. There we learn that sometimes the righteous are oppressed and defeated, and meanwhile the wicked prosper and experience joy. In Ecclesiastes, life is vapor, a grasping after the wind, an attempt to understand the impossible, the incomprehensible. Ecclesiastes says that life frequently does not make sense. In Job, Job seems to be arguing with Ecclesiastes’ wisdom while Job’s friends are quoting bucketfuls of Proverbs.
I think it was JBJ that suggested that Solomon actually wrote Job. Makes sense to me.