What is the evidence from the Qur’an, the Sunnah, the sayings of the Companions, and the scholars regarding Allah’s accountability of the ruler if he does not impose the Sharia on his people, and the father if he does not impose it on his wife and children?

Among the most significant differences between the system of governance in Islam and others is that the Sharia (definition) is the source of rulings, and the interests it considers are not limited to worldly matters, but encompass both worldly and otherworldly interests. Ibn Khaldun distinguished between kingship (mulk) and caliphate (khilafah), defining the caliphate as leading the people according to the requirements of the Sharia, concerning their otherworldly and worldly interests. Establishing the Sharia is not merely one of the Caliph's duties, but rather his fundamental purpose for being appointed, and this is his primary obligation. The Caliphate is founded upon preserving religion and managing worldly affairs through it. This is the meaning of establishing Allah's Sharia among His creation, and it is the truth and justice for which books were revealed and messengers were sent. The ruler will be held accountable for this, for Allah Almighty has commanded it, just as a father is commanded concerning his household. Everyone is a guardian and responsible for his flock, and the implementation of Sharia rulings is obligatory.