The sin of Job is rebellion (Job 34:31-34:37)

“Has anyone said to God?

‘I have endured punishment.

I will not offend anymore.

Teach me what I do not see.

If I have done iniquity,

I will do it no more.’

Will he then pay back to suit you

Because you reject it?

You must choose!

Not I!

Therefore declare what you know.

Those who have sense will say to me.

The wise who hear me will say.

‘Job speaks without knowledge.

His words are without insight.’

Would that Job were tried to the limit,

Because his answers are those of the wicked.

He adds rebellion to his sin.

He claps his hands among us.

He multiplies his words against God.”

If only Job had said that he would not offend God anymore, he might have been all right. If only he had asked God what he did wrong, so that he could learn the right way. Those with any knowledge at all would say that Job spoke without knowledge. He was dumb. His words had no insight. He answered like a wicked man. He seemed to be rebellious against God in a lot of what he said. This is the accusation of Elihu against Job.