In my humble opinion,
the book of Job tells us that,
even if you are the most faithful to Lord, most well succeeded materially, with best blessed family. You still can pass through probation.
Probation doesn't always means it is for men to see and criticise it. It means that militias of heaven and hell are also watching it and waiting your final "position/answer" in front of God.
The book of Job tells us also amazing details about creation of God (chap. 38, 39, 40...)
So rich, the book of Job.
I think Job knew God well enough to know that no haughty response or rough, would bring his family back, and at the end God gave him twice as much back. Praise the Lord!
I just love this book.