Q. We recently studied the book of Job. Why does Job not mention Satan, when he’s the one behind his troubles?
Job doesn’t mention Satan because Job doesn’t know that Satan is behind his troubles. He can’t know, otherwise the purpose for his troubles would be defeated.
As I discuss the opening narrative in my study guide to the book of Job, I say:
“The book of Job has much to say about the problem of evil, that is, why there is so much suffering in the world if it’s governed by a good God. As we consider the book in detail in the sessions ahead, we’ll get many insights into this question. But here the Adversary begins by raising a different problem, the problem of good. If apparent goodness is always rewarded and bad conduct is always punished, how can we ever really be sure that a person is genuinely good and not just trying to win rewards and avoid punishment? It turns out that the only kind of universe in which genuine good can be known to exist is one in which good people sometimes suffer undeservedly but still demonstrate continuing loyalty to God.”
If God told Job, “You are suffering these things in order to prove that people can still trust me and live in the right way even when they suffer without knowing why,” then Job would know why he was suffering. In order for the test to address the “problem of good” and show that God has created a universe in which genuine good actually does exist, Job can’t know why he is suffering.
In light of this, in this session of the study guide I also ask this question for reflection and discussion:
“One of the most disturbing thoughts for readers of the book of Job is the idea that the devil could somehow trick God into allowing him to harm a loyal person of faith. But the interaction here is much more complex than that simple interpretation implies. The Adversary can only believe that Job is motivated by greed; the Lord knows that Job’s heart is actually pure and devoted. And so the Lord permits, or perhaps even arranges, a test in which the devil’s worst efforts actually disclose the truth about Job’s good heart, and about the possibility of goodness generally. If, through suffering without knowing why, you could help demonstrate for an audience on earth and in heaven that cynical, disparaging, diabolical contradictions of God’s ways are false and unfounded, would you be willing to do this?”
(You can download a copy of my Job study guide for free at this link.)
Good Question 
This raises the question, did God know in advance that Job would remain faithful, like Noah? I think the answer is that God sustained Job so he couldn’t fail. Like he sustains all his children in trials.
I think God had a thorough understanding of Job’s character, which is why he described him as an exemplary person. When the Accuser said that Job was only honoring God because God was blessing him materially, God knew that this false claim would not stand the test.
Thank you for this excellent response to my question. I’ve never thought about the “problem” of good.