Perhaps the most unique element of Job is our observation of a "divine council". God is gathered with God’s Spirits (angels?), Satan is even present. In this council, the devotion of Job is acknowledged by God and Satan challenges that devotion. It is in that challenge that a ‘wager’ is struck. God will withdraw protection from Job and Satan can reduce his life to poverty and illness. The idea is that the material blessings of Job are the reward basis of his faith.
The book is structured with the human idea then that the removal of Job's blessings are therefore punishment.
Satan as 'the accuser' is first seen in Scripture as the serpent in the Garden of Eden. Seeing this development in Job is a unique presentation of the supernatural order of things in the Bible.
The challenge that lies behind this council is the connection between material possessions and faith. Job is faithful and has been richly rewarded. The Accuser asks what will happen if those blessings are stripped away? And they are. Will Job remain faithful? His friends seem to be present to push the human presupposition that bad things that happen are punishment. The power of this book is considering God's response.
It seems to offer God's response to the age-old question of crisis and disaster, "Why?"