“It is He who sent His Messenger with guidance and the religion of truth so that He might cause it to prevail over every other religion, and Allah is sufficient as Witness.” (al-Fath 48:28)

The assertion of those who say, “The Torah brought justice and the Gospel brought grace; therefore we have no need of anything beyond the two—even supposing that assertion to be true,” would only be sound if both Scriptures had remained unchanged, were still being followed in belief and practice, and if their adherents were, by virtue of that, aided and granted victory over their opponents. But how can that stand when so much of each book has been altered, and when their communities are not triumphant over the rest of the unbelievers? On the contrary, the unbelievers dominate them across most of the earth—Yemen, the Ḥijaz, the rest of the Arabian Peninsula, Iraq, Khurasan, the Maghrib, India, Sind, and the lands of the Turks. In the hands of the People of the Scripture there remained only al-Shām, Egypt, and a few other territories, yet even there the Persians overpowered them. Thereafter Allah caused the Christians to vanquish the Persians, and that victory was but a paving of the way and a preparation for the eventual manifestation of the religion of Islam.

Thus, when the Magian Persians defeated the Romans, the Prophet—may Allah bless him and grant him peace—was distressed