Allah has commanded us to enjoin the good and forbid the evil, and this duty cannot be rendered without power and authority. Likewise, all other social duties such as jihād, maintaining peace and order, justice, organizing ḥajj and ‘īd festivals, redressing abuses, helping the oppressed, enforcing the ḥudūd, and so on, cannot be carried out without political power and authority.
The Caliphate 