So when He said in the verse on righteousness:

“Those are the ones who have been truthful, and those are the God-fearing,”

this indicated that they were truthful in saying, “We believe,” for this was the declaration they were commanded to make and which they used to utter. They were not commanded to declare, “We are righteous,” or, “We are virtuous.” Rather, when a man says, “I am righteous,” he is praising himself. Thus, Zaynab bint Jahsh was originally named Barrah (“righteous”), but people said, “She is praising herself,” so the Prophet, may Allah bless him and grant him peace, named her Zaynab.

This differs from professing faith by saying, “We believe,” for they were obliged to say this. He, exalted is He, said:

“Say, ‘We believe in Allah and what has been revealed to us, and what was revealed to Abraham, Ishmael, Isaac, Jacob, and the Tribes, and what Moses and Jesus were given, and what the prophets were given from their Lord.’”

Likewise, near the beginning of Āl ‘Imrān:

“Say, ‘We believe in Allah and what has been revealed to us, and what was revealed to Abraham, Ishmael, Isaac, Jacob, and the Tribes, and what Moses, Jesus, and the prophets were given from their Lord.’”

He, exalted is He, also said:

“The Messenger believes in what has been revealed to him from his Lord, as do the believers. All believe in Allah, His angels, His Books, and His messengers: ‘We make no distinction between any of His messengers.’”

His words, “We make no distinction,” show that they said, “We believe, and we make no distinction.” Hence He said:

“And they say, ‘We hear and obey.’”

They thus combined their declaration, “We believe,” with their declaration, “We hear and obey.”

In the verse on righteousness, He said:

“And those are the God-fearing.”

He thus identified the righteous with the God-fearing when these terms are used independently and without qualification. Yet He distinguished between them when they are paired and qualified, in His words:

“And cooperate in righteousness and piety.”

This verse indicates that faith, righteousness, and piety denote the same thing when used without qualification: the believers are the God-fearing, and they are the righteous.