Table of Contents
Growth and Weakening of Faith
Faith in Islam is not a fixed, unchanging state in the heart. It can grow stronger and it can also become weaker. This idea is very important, because it teaches a Muslim not to feel completely safe from losing faith, and also not to despair if faith feels low. Instead, a Muslim learns to work on faith as something living that needs care and protection.
The scholars of Ahl al Sunnah wal Jamaʿah agree that īmān increases and decreases. It increases through obedience to Allah and decreases through disobedience and neglect. This is based on the Quran, the Sunnah, and the understanding of the earliest Muslims.
Foundational rule: Īmān in the heart is not static. It increases with obedience and remembrance of Allah and decreases with sin and heedlessness.
Quranic Proofs That Īmān Increases
The Quran clearly speaks about faith increasing. Allah describes believers whose faith grows when they hear His verses. Allah says:
“And when His verses are recited to them, it increases them in faith, and they put their trust in their Lord.”
(Qur’an 8:2)
Here Allah mentions an increase of īmān that happens when the Quran is recited. This shows that īmān can grow.
Allah also says:
“And whenever a surah is revealed, there are some of them who say, ‘Which of you has this increased in faith?’ As for those who believe, it has increased them in faith, and they rejoice.”
(Qur’an 9:124)
The verse states clearly that the revelation of a new surah increases the faith of believers. This proves that īmān is something that can move upward. The hypocrites, on the other hand, do not benefit from the revelation.
Allah says about the believers at the time of the Battle of the Trench:
“And when the believers saw the confederates, they said, ‘This is what Allah and His Messenger had promised us, and Allah and His Messenger spoke the truth.’ And it increased them only in faith and submission.”
(Qur’an 33:22)
A great trial and a frightening army came against them, but instead of their faith collapsing, their faith increased. This shows that tests, when faced with trust in Allah, can raise the level of īmān.
From these and other verses, the scholars took the principle that īmān is not just a simple feeling. It is something that responds to Allah’s signs. When the heart receives these signs with acceptance, īmān grows stronger and more complete.
Important principle: The Quran and its verses are a cause for the increase of faith in the hearts of believers.
Indications That Īmān Can Decrease
The Quran also speaks of people whose faith becomes weak or who lose faith. This would not be possible if īmān was a fixed, unchangeable state.
Allah mentions some people who feel safe and strong when things are easy, but when hardship comes their inner reality is revealed. Allah says:
“And of the people is he who worships Allah on an edge. If he is touched by good, he is reassured by it. But if he is struck by a trial, he turns on his face. He loses this world and the Hereafter. That is the clear loss.”
(Qur’an 22:11)
This person has a very fragile kind of īmān, not deep, not stable. When a trial comes, he turns away. This shows that what he had can be weakened and even destroyed.
Allah also says:
“And when a surah is revealed, there are some of them who say, ‘Which of you has this increased in faith?’ As for those who believe, it has increased them in faith and they rejoice. But as for those in whose hearts is a disease, it adds filth to their filth, and they die while they are disbelievers.”
(Qur’an 9:124–125)
The same revelation that increases the faith of believers adds more disease and corruption to the hearts of the diseased. This shows the opposite path. Instead of īmān growing, the impurity of the heart increases.
In many verses, Allah describes people “whose hearts became hardened” or who “turned back on their heels.” These expressions point to a decline or loss of faith, which means that īmān is not fixed and can go down.
The Prophetic Explanation of Increasing and Decreasing Īmān
The Sunnah explains the nature of īmān very clearly. The Prophet ﷺ taught that īmān includes statements, actions, and inner beliefs, and that not all believers have the same level of faith.
In an authentic hadith he ﷺ said:
“Faith has sixty odd or seventy odd branches. The highest of them is the statement ‘Lā ilāha illallāh,’ and the lowest of them is removing something harmful from the road. And modesty is a branch of faith.”
(Muslim)
This hadith shows that īmān is made up of many branches. Some parts are very high and central, like the testimony of faith. Some parts are smaller, like removing harm from the path. A person can have some branches stronger than others. As he practices more branches, his īmān increases. If he neglects or abandons them, his īmān decreases.
The Prophet ﷺ also described different degrees of faith in the context of modesty and lowering the gaze. He said:
“The zina of the eyes is looking, the zina of the tongue is speaking, and the soul desires and wishes. The private parts confirm that or deny it.”
(Bukhari and Muslim)
Committing sins such as forbidden looking or speaking is part of disobedience. These sins do not remove faith completely from a Muslim as long as he still believes, but they certainly damage and weaken the quality of īmān in the heart.
He ﷺ also said:
“None of you truly believes until his desire follows what I have brought.”
(Reported by al Nawawi in al Arbaʿīn, authenticated by some scholars)
This hadith shows that there are degrees of perfection in faith. The phrase “truly believes” here refers to completion of faith, not the basic existence of faith. A person may have basic īmān but not reach the level where his desires fully follow the guidance of the Prophet ﷺ. This again points to different levels of faith, which is another way of saying that īmān increases and decreases.
Key statement: The many “branches of faith” mentioned by the Prophet ﷺ prove that faith has levels, so it can grow more complete or become more deficient.
Difference Between the Basis of Faith and Its Levels
To understand increase and decrease properly, it is helpful to distinguish between the basic foundation of īmān and its higher levels.
The basic foundation of īmān is accepting Allah as the only Lord and God, believing in His Messenger ﷺ, and believing in the pillars of faith. As long as this core remains, the person is a believer in the general sense, even if he commits many sins.
Above this foundation there are higher levels of īmān and excellence, with more obedience, more love and fear and hope in Allah, more sincerity, and more constant remembrance. The more a Muslim acts righteously and purifies his heart, the more he climbs in these levels.
When we say īmān increases and decreases, we are mostly speaking about these levels and quality. The core itself can also be threatened in extreme cases, such as when someone commits acts or beliefs that remove a person from Islam completely, but that belongs to the topic of kufr and hypocrisy and the issue of takfīr which is treated in other chapters.
The Prophet ﷺ hinted at the idea of fluctuating faith when he said, describing the sweetness of faith:
“There are three qualities, whoever has them will taste the sweetness of faith: that Allah and His Messenger are more beloved to him than anything else, that he loves a person only for the sake of Allah, and that he hates to return to disbelief after Allah has saved him from it, just as he hates to be thrown into the Fire.”
(Bukhari and Muslim)
To “taste” the sweetness of faith implies that faith can be experienced as stronger and more intense. If someone loses these qualities, he has not lost the name of faith completely, but his faith is no longer at that sweet, high level.
How Obedience Increases Faith
Obedience to Allah increases faith in several connected ways.
When a Muslim performs acts of worship sincerely, his heart fills with remembrance of Allah. Allah praises those whose faith grows through obedience:
“The believers are only those who, when Allah is mentioned, their hearts tremble, and when His verses are recited to them, it increases them in faith, and upon their Lord they rely, those who establish prayer and spend from what We have provided them. Those are the true believers.”
(Qur’an 8:2–4)
In these verses, the trembling heart, the increase of faith when hearing the Quran, the establishment of prayer, and spending in charity are all mentioned together. The life of worship and trust in Allah raises the believer to the level of “true believers.”
Acts such as prayer, fasting, reciting the Quran, giving charity, remembering Allah, and showing good character are all parts of īmān. When they are performed, they strengthen the belief in the heart. The more a person obeys, the more his īmān becomes firm and bright.
The Prophet ﷺ encouraged additional acts that increase the light of faith. He said regarding the night prayer:
“Hold fast to the night prayer, for it was the way of the righteous before you, it brings you closer to your Lord, it is an expiation for bad deeds, and it prevents sin.”
(Reported by al Tirmidhi, graded hasan)
As sins are removed and prevented, faith grows. This shows that acts of devotion not only express faith but also feed and grow it.
Important rule: Every sincere act of worship and every form of obedience is a branch of faith. Performing these branches multiplies and strengthens īmān.
How Sin and Neglect Decrease Faith
Sin darkens the heart and weakens faith. The more a person disobeys, the more his connection to Allah becomes weak, unless he repents and returns.
The Prophet ﷺ described how sins leave marks on the heart:
“When a servant commits a sin, a black dot is placed upon his heart. If he gives it up, seeks forgiveness, and repents, his heart is polished. But if he returns, it increases until it covers his heart. That is the ‘ran’ (covering) which Allah mentioned: ‘No, rather, the stain has covered their hearts because of what they used to earn.’”
(Reported by al Tirmidhi, authenticated by al Albani, referring to Qur’an 83:14)
This covering over the heart blocks the light of īmān, so the person no longer feels the same desire to worship, or the same fear of Allah, or the same love of obedience. His faith has decreased.
Allah warns about people whose hearts become hard through constant wrongdoing:
“Then your hearts became hardened after that, so they were like stones, or even harder.”
(Qur’an 2:74)
Hardness of the heart is the opposite of soft, living faith. When the heart becomes hard, it is difficult for remembrance of Allah to reach it. This is a clear sign of a serious decrease in īmān.
Even if a Muslim still believes, sins can drag his faith downward. In another hadith the Prophet ﷺ said:
“A fornicator does not commit fornication while he is a believer, a thief does not steal while he is a believer, and a drunkard does not drink wine while he is a believer.”
(Bukhari and Muslim)
The scholars explained that this does not mean that he is no longer a Muslim at all. It means that while he is committing such major sins, his faith is very weak and incomplete. The light of īmān is pushed aside by the darkness of the sin. This is a powerful proof that īmān has degrees and can be very low at some times.
Serious warning: Every sin, especially major sins, eats away at the strength and purity of faith, even if basic belief remains.
The Natural Fluctuation of Faith in Daily Life
Even without major sins, the everyday life of a believer shows that īmān goes up and down. The companions themselves experienced this and spoke about it.
A famous companion, Hanzalah, once said, “Hanzalah has become a hypocrite,” because he noticed his state with the Prophet ﷺ was not like his state when he was with his family. When the Prophet ﷺ asked him, Hanzalah explained that when they were with the Prophet ﷺ it was as if they were seeing Paradise and Hellfire, but when they left, they became busy with family and work. The Prophet ﷺ said:
“By Him in Whose Hand is my soul, if you were to remain in the state you are in when you are with me and in remembrance, the angels would shake hands with you in your beds and on your roads. But, O Hanzalah, there is a time for this and a time for that.”
(Muslim)
This hadith shows that feeling lower in faith sometimes is part of being human. It does not automatically mean hypocrisy. The heart is affected by surroundings, company, and what a person is thinking about.
However, while normal fluctuation is expected, a believer should be careful not to accept a permanent low level. Instead, he should use the times of strong faith to build habits and seek knowledge, so that in weaker times he does not fall into disobedience.
Practical Meaning for the Muslim
Knowing that īmān increases and decreases has important effects on how a Muslim lives.
First, it teaches hope. If someone feels that his faith is weak, he knows that it can grow. He is not trapped. By turning back to Allah, remembering Him, and performing good deeds, his īmān can rise again. Allah says:
“Except for those who repent, believe, and do righteous deeds. For them Allah will replace their evil deeds with good. And Allah is ever Forgiving, Merciful.”
(Qur’an 25:70)
Second, it teaches fear and caution. A person cannot rely on a past moment of strong faith and then neglect his duties. Because īmān can decrease, he must constantly ask Allah for firmness. The Prophet ﷺ, even though he was the Messenger of Allah, used to say often:
“O Turner of the hearts, keep my heart firm upon Your religion.”
(Reported by al Tirmidhi, authenticated by al Albani)
If the Prophet ﷺ asked for firmness, then others are even more in need of making this supplication and being careful about the state of their faith.
Third, this understanding protects a Muslim from two extremes. One extreme is to say that as long as a person believes in the heart, actions do not matter. The other extreme is to say that any sin removes faith completely. The balanced view is that sins reduce faith and may even remove its perfection, but do not necessarily remove the name of belief, as long as the foundations remain.
Balanced view: Ahl al Sunnah say: īmān consists of belief in the heart, speech of the tongue, and actions of the limbs. It increases with obedience and decreases with disobedience.
Conclusion
In Islam, faith is a living reality inside the heart that shows itself on the tongue and through actions. The Quran and Sunnah both teach that īmān increases through belief, remembrance, and obedience, and decreases through sin, neglect, and hardening of the heart.
This means that a Muslim should always be working on his faith. When faith is strong, he should be grateful and use that strength for more good deeds. When faith is weak, he should seek forgiveness, remember Allah, and renew his connection to the Quran and the Sunnah.
By understanding that īmān rises and falls, a believer can live between hope and fear, always turning to Allah, asking Him for guidance and firmness until he meets Him.