Today’s Qur’an reading prescribes violence until the world is Islamized:
And fight them until there is no fitnah and [until] the religion, all of it, is for Allah. And if they cease – then indeed, Allah is Seeing of what they do. (Qur’an 8:39)
Fitnah is disturbance, upheaval, disorder, chaos. According to numerous early Muslim authorities, including Ibn Abbas, Abu Al-`Aliyah, Mujahid, Al-Hasan, Qatadah, Ar-Rabi` bin Anas, As-Suddi, Muqatil bin Hayyan and Zayd bin Aslam, the statement that Muslims must fight until there is no more fitnah means that they must fight “so that there is no more Shirk.”
Shirk is the association of partners with Allah — i.e., calling Jesus the Son of God. So this verse, although it was revealed in the aftermath of a seventh-century battle between Muslims and pagans, has a universal application: the Tafsir al-Jalalayn glosses it this way: “And fight them until sedition, idolatry, is, exists, no more and religion is all for God, alone, none other being worshipped”¦”
Muhammad himself said: “I have been commanded to fight against people so long as they do not declare that there is no god but Allah, and he who professed it was guaranteed the protection of his property and life on my behalf except for the right affairs rest with Allah.” (Sahih Muslim 30)