We believe that the second among the degrees of the religion is faith. This is included in the Prophet's answer to Jibrīl (peace be upon him) when he asked him about faith: "Tell me about faith." He (may Allah's peace and blessings be upon him) said: "It is to believe in Allah, His angels, books, messengers, the Last Day, and destiny, the pleasant and unpleasant aspects thereof." He said: "You have spoken the truth... Then, he left, and I remained for a short while. Then, the Messenger of Allah (may Allah's peace and blessings be upon him) said to me: "O ‘Umar, do you know who that questioner was?" I said: "Allah and His Messenger know best." He said: "That was Jibrīl, who came to teach you your religion." [Narrated by Muslim (8), Abu Dāwūd (4695), At-Tirmidhi (2610), An-Nasā’i (4990), and Ibn Mājah (63)]
Although the Prophet (may Allah’s peace and blessings be upon him) specifically defined faith, in the Hadīth of Jibrīl, as belief "in Allah, His angels, books, messengers, the Last Day, and destiny, the pleasant and unpleasant aspects thereof", faith also refers to a more comprehensive meaning that combines all goodness, and includes all acts of the heart and the body. Allah Almighty says: {The true believers are those whose hearts are filled with awe when Allah is mentioned, and their faith increases when His verses are recited to them, and they put their trust only in their Lord; those who establish prayer and spend out of what We have provided for them. Such are the true believers; they will have high ranks with their Lord, and forgiveness and an honorable provision.} [Surat al-Anfāl: 2-4]
Also, the Prophet (may Allah’s peace and blessings be upon him) defined faith to the delegation of ‘Abdul-Qays as the performance of outward rites. Ibn ‘Abbās (may Allah be pleased with him) reported: When the delegate of ‘Abdul-Qays came to the Messenger of Allah (may Allah’s peace and blessings be upon him), he said: "Who are the delegation?" They said: "The delegation are from the tribe of Rabī‘ah." The Prophet (may Allah’s peace and blessings be upon him) said: "Welcome, O people - or the delegation - You will not have any disgrace or regret." They said: "O Messenger of Allah, between you and us there are the infidels of the tribe of Mudar; so please order us with something clear, so we inform those who are behind us about it, and by which we may enter Paradise." They also asked about drinks. He ordered them to do four things and forbade them from four things. He ordered them to believe in Allah alone, and asked them: "Do you know what is meant by belief in Allah alone?" They said: "Allah and His Messenger know best." He said: ''To testify that none is worthy of being worshiped except Allah and that Muhammad is the Messenger of Allah, to establish prayer, to pay Zakah, to fast Ramadan, and to give one fifth of the war booty." Then he forbade four (drinking utensils): ad-dubā’ (pumpkin), al-hantam (dyed utensil with grease), and an-naqīr (pierced date palm), al-muzaffat, or probably al-muqayyar (tar-coated utensils)." And then the Prophet (may Allah’s peace and blessings be upon him) said: "Remember all these things by heart and convey them to those you have left behind." [Narrated by Al-Bukhāri (53), Muslim (17), Abu Dāwūd (3692), At-Tirmidhi (2611), and An-Nasā’i (5031)]
Al-Bukhāri (may Allah have mercy upon him) set a chapter about this meaning in his Sahīh; it reads: Chapter on the Matters of Faith and the Verse that Says: {It is not righteousness to turn your faces towards the east or the west, but righteousness is to believe in Allah, the Last Day, the angels, the Scriptures, and the prophets; and to give charity out of one’s cherished wealth to relatives, orphans, the needy, the wayfarer, beggars, and to free slaves; to establish prayer and give Zakah; to fulfill the ratified pledges; to be patient at times of hardship, adversity, and during the battle. Such are the true believers, and such are the righteous.} [Surat al-Baqarah: 177]
We believe that faith consists of words, deeds, and belief. The Prophet (may Allah’s peace and blessings be upon him) said: "Faith has over seventy branches - or over sixty branches - the uppermost of which is the declaration 'No one is worthy of being worshiped except Allah', and the least of which is the removal of a harmful object from the road; and modesty is a branch of faith." [Narrated by Al-Bukhāri (9), Muslim (35), and this is his version, Abu Dāwūd (4676), At-Tirmidhi (2614), An-Nasā’i (5005), and Ibn Mājah (57)]
We believe that the believers excel one another in terms of good deeds. Abu Sa‘īd al-Khudri (may Allah be pleased with him) reported: The Messenger of Allah (may Allah’s peace and blessings be upon him) said: "When the people of Paradise enter Paradise and the people of Hellfire go to Hellfire, Allah will order those who have had faith in their hearts equal to the weight of a grain of mustard seed to be taken out from Hellfire. So, they will be taken out, but they will be blackened. Then, they will be put in the river of Haya or Hayāt - the narrator is in doubt - and they will revive like a grain that grows near the bank of a flood channel. Do you not see that it comes out yellow and twisted?" [Narrated by Al-Bukhāri (22) and Muslim (184)]
Abu Umāmah ibn Sahl ibn Hanīf related that he heard Abu Sa‘īd al-Khudri (may Allah be pleased with him) report that the Messenger of Allah (may Allah’s peace and blessings be upon him) said: "While I was sleeping, I saw the people being shown to me, and they were wearing shirts. Some reached the breast and some reached lower than that. And ‘Umar ibn al-Khattāb was shown to me, and he was wearing a shirt that he was dragging." They said: "How do you interpret that, O Messenger of Allah?" He said: "The religion." [Narrated by Al-Bukhāri (23), Muslim (2390), At-Tirmidhi (2285), and An-Nasā’i (5011)]
We believe that faith increases and decreases; it increases with good deeds and decreases with sins. Allah, Exalted be He, says: {We relate to you their story in truth. They were youths who believed in their Lord, and We gave them more guidance.} [Surat al-Kahf: 13] He also says: {And the believers may increase in faith.} [Surat al-Muddaththir: 31]
And the Prophet (may Allah’s peace and blessings be upon him) said: "Whoever says 'none is worthy of being worshiped except Allah' and has in his heart good equal to the weight of a barley grain will be taken out of Hellfire. And whoever says 'none is worthy of being worshiped except Allah' and has in his heart good equal to the weight of a wheat grain will be taken out of Hellfire. And whoever says 'none is worthy of being worshiped except Allah' and has in his heart good equal to the weight of an atom will be taken out of Hellfire." [Narrated by Al-Bukhāri (44), Muslim (193), and At-Tirmidhi (2593)]
‘Umar ibn ‘Abdul-‘Azīz wrote to ‘Adyy ibn ‘Adyy, saying: "Indeed, faith has certain duties, laws, limits, and Sunnahs. Whoever fulfills them has fulfilled faith, and whoever does not fulfill them has not fulfilled faith. If I live longer, I will explain them to you so that you can act upon them; and if I die, I am indeed not keen to remain in your company." [Narrated by Al-Bukhāri as mu‘allaq (1/10), Ibn Aby Shaybah in Al-Musannaf (31084) and in Al-Imān (135), Al-Khallāl in As-Sunnah (1162, 1553), Ibn Battah in Al-Ibānah (1166), and Al-Lālikā’i in Sharh Usūl I‘tiqād Ahl As-Sunnah Wa Al-Jamā‘ah (1572)]
Mu‘ammar, Sufyān ath-Thawri, Mālik ibn Anas, Ibn Jurayj, and Sufyān ibn ‘Uyaynah used to say: "Faith consists of words and deeds, and it increases and decreases." [Al-Ibānah Al-Kubra (2/806) and Ash-Sharī‘ah for Al-Ājurri (2/606)]
Al-Hāfizh Abu Bakr ‘Abdullāh ibn az-Zubayr al-Humaydi said: "And that faith consists of words and deeds and it increases and decreases. Words are not useful without deeds; words and deeds are not useful without a sincere intention; and words, deeds, and intention are not useful without compliance with the Sunnah." [Usūl As-Sunnah for Al-Humaydi (37)]
And Al-Khallāl said: "‘Abdul-Malik al-Maymūni related to me: Ya‘la ibn ‘Ubayd told me more than sixty years ago: "Faith consists of words and deeds. He who fasts, prays, and performs good deeds has greater faith than he who steals and commits adultery." [As-Sunnah for Abu Bakr al-Khallāl (3/590)]
Ibn Abi Hātim said: "I asked my father and Abu Zur‘ah about the doctrines of Ahl As-Sunnah on Usūl ad-Dīn and what they know of the views of the scholars in the different countries and places, and what they think about that. They both said: We lived at the time of scholars from different places - the Hejaz, Iraq, the Levant, and Yemen - and their doctrine includes the principle that: faith consists of words and deeds, and it increases and decreases." [Sharh Usul I‘tiqād Ahl As-Sunnah Wa Al-Jamā‘ah (1/198), and ‘Aqīdat As-Salaf - the Introduction by Ibn Abi Zayd al-Qayrawāni to his book Ar-Risālah (29)]
Al-Lālikā’i said: "Faith consists of words and deeds, a view held by the scholars: Mālik ibn Anas, ‘Abdul-‘Azīz ibn Abi Salamah al-Mājeshūn, Al-Layth ibn Sa‘d, Al-Awzā‘i, Sa‘īd ibn ‘Abdul-‘Azīz, Ibn Jurayj, Sufyān ibn ‘Uyaynah, Fudayl ibn ‘Iyād, Nāfi‘ ibn ‘Umar al-Jumahi, Muhammad ibn Muslim at-Tā’ifi, Muhammad ibn ‘Abdullāh ibn ‘Amr ibn ‘Uthmān ibn ‘Affān, Al-Muthanna ibn as-Sabbāh, Ash-Shāfi‘i, ‘Abdullāh ibn az-Zubayr al-Humaydi, Abu Ibrāhīm al-Muzani, Sufyān ath-Thawri, Shareek, Abu Bakr ibn ‘Ayyāsh, Wakī‘, Hammād ibn Salamah, Hammād ibn Zayd, Yahya ibn Sa‘īd al-Qattān, ‘Abdullāh ibn al-Mubārak, Abu Is-hāq al-Fazāri, An-Nadr ibn Muhammad al-Marūzi, An-Nadr ibn Shamīl, Ahmad ibn Hanbal, Is-hāq ibn Rahaweih, Abu Thawr, and Abu ‘Ubayd." [Sharh Usul I‘tiqād Ahl As-Sunnah Wa Al-Jamā‘ah for Imām Al-Lālikā’i (4/913)]
In his book "Usūl As-Sunnah", Abu ‘Abdullāh ibn Abi Zamanayn said: "Chapter on the view that faith consists of words and deeds: Ahl-us-Sunnah say: Faith is sincerity to Allah within the hearts, proclamation by the tongues, and actions by the body parts with good intention and in compliance with the Sunnah." [Usūl As-Sunnah (207)]