He would like to know why God punished one of his most faithful servants?
Punishment implies wrongdoing, but Job was a righteous man so this was NOT punishment. The suffering was inflicted upon Job by Satan.
8 The LORD said to the satan, “Have you noticed my servant Job? There is no one on earth like him, blameless and upright, fearing God and avoiding evil.”
Why couldn’t God have just told Satan to go away, because he is so much more powerful than Satan?
He could have done that. But, the point of the story is the lesson it contains. It is not about any “need” of God. He needs nothing.
Notice that the devil actually seeks “permission” of God to perform this “test”.
9 The satan answered the LORD and said, “Is it for nothing that Job is God-fearing? 10 Have you not surrounded him and his family and all that he has with your protection? You have blessed the work of his hands, and his livestock are spread over the land. 11 But now put forth your hand and touch all that he has, and surely he will curse you to your face.”
God is also able to limit the suffering. Both of these tell us that satan already acknowledges God’s power.
12
The LORD said to the satan, “Very well, all that he has is in your power; only do not lay a hand on him.” So the satan went forth from the presence of the LORD.
Why did he feel the need to “prove his power” to Satan by causing suffering to Job and his family?
This is a literary composition, and not a transcript of historical events and conversations. God is not proving anything to satan except as part of the plot line of the fictional event. The writer is trying to teach a lesson about faith, trusting in the Lord, seeking the Lord, and the purpose of suffering.
And why should we worship a God who causes suffering to those who are faithful to him?
In this dramatic literary piece God DOES NOT cause the suffering. The devil persecutes Job and God allows it. Ultimately it is an expression of the strength of faith over evil provided we continue to behave in an upright way despite any suffering we endure trusting in God always.
Suffering happens for a variety of reasons, but they all stem from the presence of sin in the world.
And remember that God does restore Job in the end.