The entire purpose of Islam, according to all Islamic doctrine, is to ensure that there is an Islamic state throughout the entire world called a caliphate. And under that, Sharia or Islamic law is the law of the land. That's it.

The entire purpose of Islam, according to all Islamic doctrine, is to ensure that there is an Islamic state throughout the entire world called a caliphate. And under that, Sharia or Islamic law is the law of the land. That's it. Islam breaks the entire world into two parts. The Dar al-Islam, where Sharia is the law of the land, and the Dar al-Harb, the house or abode of war, where there is not Sharia as the law of the land. The function of Islam is to eliminate the Dar al-Harb until the entire world is a Dar al-Islam.