I've found that any given scripture can be used by God for multiple purposes with multiple people and even with me. From one year to the next, I learn different things even from the same scripture as my life circumstances change and my life with God progresses.
So there isn't any single purpose to be claimed for any scripture.
Something I've noted in my more recent readings of Job is that Job is the specific scriptural example of the man who knows God through His creation.
Job is a Psalm 19 believer and the antithesis of those Paul speaks of in Romans 1. Unlike them, Job has recognized God in creation and acknowledged Him as God.
It's been long recognized by scholars that Job appears to have no connection to Abraham and there's not even a connection given to Noah or Adam--no geneology leading to anyone else in scripture is provided. Job is just out there as a believer unto himself.
I have noted that--uniquely to the book of Job--the discussion of God and His sovereignty is in terms of creation itself rather than covenants or promises or deeds done for patriarchs. Nowhere else does God identify Himself solely in terms of His creation of the stars, His creation of the great beasts of sea and land, His control of the great forces of nature. In Job, God is the creator and master of the universe, and that's how Job knows Him.
In the book of Job, God is not the God of Abraham or the "God of your forefathers." God is the God of creation, the Sovereign of the Universe. The opening vignette of God commanding Satan reminds us that Satan is also firmly under God's dominion.
This is identified by Job himself when he assigns all that happens to him--good and bad--as happening under God's authority: "The Lord gives, the Lord takes away. Blessed be the name of the Lord." And the scripture immediately affirms that by acknowledging the Lord's authority over all matters, pleasant and unpleasant, Job has not "blamed" God.
So within Job we see the total sovereighty of God given in all areas. And we should also note from the New Testament perspective given in Colossians 1 that God as we see Him in Job is actually God the Son. This becomes more poignant in Job 9 when Job cries out for a "mediator between God and me who can lay hands upon us both," and we realize (thanks to Hebrews 9) that the Mediator Job calls for is Jesus. Job doesn't know the name of Jesus, but he knows he needs Jesus.