This is how I see it:
In the Bible, "rebuke" signifies a strong expression of disapproval or criticism, often used to correct or reprove someone for wrong behavior or actions, aiming to bring about repentance or change.
In a biblical context, "mock" signifies treating someone or something with scorn, contempt, or ridicule, often involving disrespect or dismissal, and is frequently associated with unbelief, pride, and rebellion against God