But once further Quranic revelation has come down, Allah and His Messenger have imposed additional obligations, and a person is able to fulfil them, he no longer deserves reward merely on the basis of what previously entitled him to it. Hence these scholars say: “He is no longer a believer merely by virtue of what previously made him a believer.” This is because the faith prescribed for one person is greater than that prescribed for another. Likewise, someone able to perform Hajj has an obligation that someone unable to perform it does not, and a person of wealth owes zakat that a poor person does not. There are many similar examples.

As for variations in faith on the servant’s part, one person may surpass another in affirmation and deeds. Everyone knows that the states of the heart vary in degree. Indeed, a person finds within himself, at some times more than at others, greater love for Allah and His Messenger, greater fear of Allah, greater hope in His mercy, greater reliance upon Him, and greater sincerity.

Likewise, knowledge and assent vary in degree, according to the sounder of the two views. This is also the sounder of the two positions reported from Ahmad. More than one Companion, including ʿUmar ibn Habīb al-Khatmī and others, said:

“Faith increases and decreases. When we remember Allah, praise Him, and glorify Him, that is its increase; when we become heedless, forget, and neglect our duties, that is its decrease.”

For this reason, qualifying one’s profession of faith is recommended. Many of the early generations—the Companions, the Successors, and others—qualified their professions of faith, while others rejected such qualification