What is the ruling on one who believes that the verses of qisas (retribution) and the punishment for theft in the Quran are aggression and assault, and claims that whoever adheres to them should be imprisoned according to man-made laws, and what should be done about him?

This statement is clear disbelief, by which its utterer exits the fold of Islam. This is because whoever claims that the punishment of an oppressor or the implementation of hudud (punishments prescribed by Islamic law) is barbaric or unjust has mocked and disparaged the religion. This falls under indirect mockery of the religion, similar to someone who believes that Islam is not suitable for the present age, or that its hudud are harsh and barbaric. One who is in this state should be invited to Islam and debated with in the best manner. If they do not desist, then their error should be publicly clarified to people if they are spreading their falsehood. Among the means of denouncing them is boycotting and shunning them.