the Sunnah: that faith does not admit of division into parts, but is a single whole—either all of it is present or none of it is.

Related to this is the need to understand that faith is one of the terms used in the revealed scriptures, the Quran, and the prophetic teachings, and belongs to religion and revealed law. What it denotes therefore varies in extent and character with the different divine scriptures. Some of it is shared by all believers, earlier and later, and by all divine scriptures: acknowledging Allah and the Last Day, worshipping Allah alone without any partner, truthfulness, and justice.

Know that most of the Meccan surahs, which Allah revealed in Mecca, concern this general faith shared by all prophets and all believers. This shared foundation is broader and more fully developed in some religious dispensations. What Muhammad, may Allah bless him and grant him peace, brought concerning Allah’s names and attributes and the description of the Last Day is more complete than what the other prophets brought.

Other aspects vary between revealed laws and prescribed ways, such as the direction of prayer, rites of worship, the prescribed amounts, times, and forms of worship, established practices, rulings, and other matters. Thus, what faith and religion denoted at the beginning of Islam is not what they denoted at the end of the prophetic period; rather, what they denoted at the end was more complete. As Allah Most High said:

“Today I have perfected your religion for you.”

And He said in the same surah:

“Whoever rejects faith, his deeds have come to nothing.”

For this reason, Imam Ahmad said: “At the beginning of Islam, faith was incomplete, and then it gradually became complete.” Likewise,