He also said—may Allah have mercy on him:

Section

It is well known that the foundation of “faith” is faith in Allah and His Messenger. This is also the foundation of knowledge of Allah, as I explained at the beginning of this volume (*).

As for “faith in Allah,” humanity at large has generally acknowledged it, apart from fringe sects such as the Dahrī philosophers, the Ismā‘īliyyah, and others like them, or those who hypocritically profess it while outwardly claiming adherence to the religions. The differences among the adherents of religions concern His names, attributes, actions, rulings, the worship due to Him, and similar matters.

As for “faith in the Messenger,” this is the crucial matter, for faith in Allah is incomplete without faith in him, and neither salvation nor happiness can be attained without it, since he is the way to Allah, glorified be He. Hence the two pillars of Islam are:

“I bear witness that none has the right to be worshipped but Allah, and I bear witness that Muhammad is His servant and Messenger.”

It is well known that faith is acknowledgment, not merely assent. Acknowledgment involves the heart’s affirmation, which is assent, and the heart’s action, which is submission—believing the Messenger