Certainly, there are consequences to sin, and self-examination with repentance is healthy in most any circumstance. But Job's example shows us that these types of questions, which often badger us in the midst of long term suffering, miss the entire point of what's truly going on. The answer to why in Job's case was simply the importance of God's testimony in the heavenly realm. There was no lesson that Job needed to learn that led to him being chosen for suffering (though he certainly did learn some valuable lessons along the way). There was no flaw God was trying to correct and no sin of which God was leading him to repent. No, it was just God's testimony in the heavenly realm. It was completely about silencing Satan and none about Job's flaws or inadequacies.
This is illustrated well in another story in which God clearly allows suffering – the raising of Lazarus in John 11.
John 11 1 Now a certain man was ill, Lazarus of Bethany, the village of Mary and her sister Martha. 2 It was Mary who anointed the Lord with ointment and wiped his feet with her hair, whose brother Lazarus was ill. 3 So the sisters sent to him, saying, “Lord, he whom you love is ill.” 4 But when Jesus heard it he said, “This illness does not lead to death. It is for the glory of God, so that the Son of God may be glorified through it.”
5 Now Jesus loved Martha and her sister and Lazarus. 6 So, when he heard that Lazarus was ill, he stayed two days longer in the place where he was. ...
17 Now when Jesus came, he found that Lazarus had already been in the tomb four days. ... 21 Martha said to Jesus, “Lord, if you had been here, my brother would not have died. 22 But even now I know that whatever you ask from God, God will give you.” 23 Jesus said to her, “Your brother will rise again.” 24 Martha said to him, “I know that he will rise again in the resurrection on the last day.” 25 Jesus said to her, “I am the resurrection and the life. Whoever believes in me, though he die, yet shall he live, 26 and everyone who lives and believes in me shall never die. Do you believe this?” 27 She said to him, “Yes, Lord; I believe that you are the Christ, the Son of God, who is coming into the world.”There are many intriguing facets of this story of suffering and redemption. I note in particular the wording of verses 5-6. Jesus loved them. I get that. But the connecting word “so” seems out of place. He loved them SO He didn't go to heal Lazarus?! That seems contradictory, yet that is exactly what the text says. We know from the end of the story what God revealed to them about Himself, that Jesus was not just someone who also believed in resurrection with them but was the actual One who holds life in His hand! By the end of the story, His love is clear – certainly because He healed Lazarus, but also because He showed Himself to be much, much bigger than they had understood to that point.
Like the story of Job, nothing in John 11 is about Mary or Martha needing to do more (or to do less). God isn't chastising Martha for not being more of a student like Mary or Mary for not being a servant like Martha. He's not punishing them for asking for His help. He's not teaching them to ask for it more. He's just revealing something of Himself. And it was a beautiful thing for them all to know.
My take away for my own suffering is simple. Suffering isn't about punishing me. It's probably not much about sanctifying me – rooting out unknown sins and replacing them with more righteous behavior – though I will likely grow in grace through suffering. Yet Satan accuses me. He prompts me to self-examine well past what is healthy and God-honoring, leaving me plagued with thoughts of my own inadequacies and failures. In reality, what God most likely wants me to learn is just that He is good, and He gives life. In the meantime, I am best served simply resting in His arms until redemption breaks forth in the storm of my own struggles.
Romans 8:18 For I consider that the sufferings of this present time are not worthy to be compared with the glory that is to be revealed to us.