Every child is born knowing that his or her Lord is Only One, Allah, regardless of what faith his or her parents may practice. But just because a child is born with this fitra, or natural belief, does not necessarily mean that the child will grow up to be what truly makes a person Muslim, which is ones iman. A Muslim must have belief and iman in the following:
1) One must belief in Allah as One God without any partners and without denying His Names and Attributes and without directing any form of worship to any other than Allah.
2) One must believe in all of Allahs noble angels without doubt and without associating any non-Islamic belief regarding them, such as them being females or human-like.
3) To be considered a believer, one must have faith in all of Allahs chosen messengers and prophets, named and unnamed without attributing to them any falsehoods or flaws.
4) One must have faith in the Divine Scriptures, but taking only the Quran as the one true guidance, preserved by Allah for all of eternity and for all of mankind.
5) One of the most important beliefs, which illustrates the purpose of life, is the belief in the Hereafter without denying any of the events told in the Quran or by the Prophet (sallallahu alaiyhi wa sallam).
6) Finally, one must believe in Divine Preordainment, more commonly known as fate or destiny. One must believe that Allah has knowledge of the future and that everything has been preordained with its due measure.
When a person accepts the above beliefs with his heart and affirms it with his tongue, he is considered as one who has iman. Iman requires acknowledgement of these beliefs through action. The Quran constantly connects ones iman with ones deeds in the phrase, Innalladhina amanu wa amilussaalihaat, which translates to those who believe and do good deeds. It is the actions a person chooses to do that both increase the iman and act as evidence of ones iman or decreases it and proves the weakness of the iman.
The Holy Prophet (sallallahu alaiyhi wa sallam) said, Iman wears out in ones heart just as the clothes (one wears) wears out. Therefore, ask Allah to renew iman in your hearts. Unfortunately, iman will not increase by only making dua and asking Allah to increase it, but it also takes effort from the believer. Allah states:
Lo! Allah does not change the condition of a people until they (first) change that which is in their hearts. (Surat ar-Rad 13:11)
There are three main causes for the decrease in ones iman. A persons iman is sure to take a fall when he loses certainty in the above six beliefs. These beliefs when properly settled into the heart play an important role in a believers life. When a person says, performs, or believes something, which is Islamically known as kufr (disbelief), their iman will be effected in a very negative way. And the final reason for the downfall of iman is performing any type of shirk. These three things all lead to sin, which is what prevents the iman from increasing.
It is a duty of every Muslim to keep his or her iman in check. This means one must constantly guard his or her iman and observe whether it has increased or decreased and for what causes. If it has decreased, one must work to increase it before it falls low enough to destroy the heart. There are many ways to increases ones iman and it involves increasing in righteous deeds and refraining from sins, as well as staying away from sinful activities and people who encourage such activities.
The first thing one should do is renew his or her faith by reciting La ilaha illallah, the meaning of which is: There is no deity except Allah, as the Prophet (sallallahu alaiyhi wa sallam) advised. A person must also believe in all the aspects of La ilaha illallah and this is done through gaining knowledge. Knowledge is one of the most essential key factors in increasing ones iman. It leads to certainty in the heart, assurance in the mind, and peace felt by the soul. Allah has said in His Holy Revelation:
It is only those who have knowledge among His slaves that fear Allah. (Surat al-Malaaikah 35:28)
An increase in knowledge leads to acknowledging Allah in every moment of ones life through taqwa, which leads to a firm iman. The type of knowledge we are discussing is knowing that Allah is One and has no partners, wives, children, or equals. It is knowing Allah through His beautiful Names and Attributes; that Allah is the Creator of the heavens and the earth and all that it contains. He is the Preserver, as well as the One Who destroys. He gives life and takes it whenever He wills. His knowledge encompasses all things and nothing can ever be hidden from Him.
And with Him are the keys of the invisible. None but He knows them. And He knows what is in the land and the sea. Not a leaf falls but He knows it, not a grain amid the darkness of the earth, nor anything wet or dry but (it is noted) in a Clear Record. (Surat al-Anaam 6:59)
He hears the cries of His servants all at once and is not confused by the countless different number of voices and languages and He is Ever Responding. He is the Compassionate, the Merciful, the Giver of Bounties. He forgives whomever He wills and punishes whomever He wills. He is the Just, the Merciful, and does no wrong to His creation. He sees all things. Not a black ant on a black stone on a black moonless night is hidden from His sight. To Him belongs all praise and glory! He is the Most Great, the Incomparable!
A person who has knowledge of Allah is no way like a person who simply states La ilaha illallah and knows nothing else about its meaning and its impact in the life of a true believer.
Likewise, a person who has knowledge about Prophet Muhammad (sallallahu alaiyhi wa sallam) and his life, noble characteristics, truthful teachings, and exemplary actions and has faith in what he informed his Ummah concerning the torment and bliss in the grave, the Last Day, the Reckoning, the questioning of ones deeds, the scale, the bridge, the rewards of Paradise, and the torments of Hellfire is unlike the person who has no such knowledge or belief. A person with this knowledge will have a purpose and goal in life, which is to obey Allah to the best of his ability and remind himself of the rewards and punishments he may earn depending upon his iman and his deeds.
There is no doubt that knowledge plays a big role in increasing the iman of a weak heart and Allah says it beautifully:
Are those who know, equal to those who know not? (Surat az-Zumar 39:9)
The second key factor, which affects the iman are ones deeds. They can either decrease the iman and weaken the heart and soul or increase it, as well as strengthening the heart and soul. Once a person gains knowledge about something, he should accept it and put it into practice. If a person accepts the forbidden as forbidden and the permissible as permissible, but refuses to act upon it, thereby disobeying Allah and committing sin, not to mention hurting his own soul, he has suppressed his iman. The basis of iman is to accept and practice.
By increasing good deeds and obedience, one nears himself to Allah, increases his iman, and purifies himself. He is less likely to fall into his base desires and worldly pleasures, keeping himself safe from the evils of society by strengthening his soul and weakening his nafs.
A person with low iman should begin by performing the obligatory duties imposed on him, such as performing the five daily prayers at their fixed times and fasting. He should stop committing major sins and eventually begin performing more voluntary and permissible acts of worship and obedience and refrain from minor sins and disliked acts to the best of his ability. When a person refrains from as many sins as possible and does as many good deeds as he can, most importantly his obligatory duties, he weakens Satan against him, which gives him a bigger chance of success. Allah says:
O you who believe! Obey Allah and obey the Messenger and do not make your deeds vain. (Surah Muhammad 47:33)
One should make sure that everything he does will only benefit him both in this world and in the hereafter. There is no point in doing something that will cause hurt to ones soul and add more weight to ones evil deeds. It is very important and beneficial to follow the Sunnah. The Prophet (sallallahu alaiyhi wa sallam) was the best of mankind and Allah chose him to show us our ways. If we follow him, we are sure to succeed in both worlds, Insha Allah. But if we reject his way and follow our own lusts or the way of the kuffar, we will only destroy ourselves. To be sure that ones deeds will increase the iman, one should do only that which Allah and His Messenger (sallallahu alaiyhi wa sallam) have taught and in that way, one can be safe from bidah and misguidance.
The third key factor to increasing ones iman is remembrance and contemplation. Remembrance refers to the remembrance of Allah, His Names and Attributes, His Greatness, Power, and Majesty, and the fact that He is the Most High. He is the Only One Who deserves to be worshipped, thanked, and depended upon. Allah is the Lord of Kindness and the Most Generous. He should be praised and glorified constantly as a part of remembrance. The Prophet (sallallahu alaiyhi wa sallam) said that the most beloved and weighty phrases of dhikr (remembrance) are La ilaha illallah Subhannallah, Alhumdulillah, and Allahu Akbar. There are many others like these, which should also be recited. The Prophet (sallallahu alaiyhi wa sallam) said, The difference between a person who glorifies his Lord and the one who does not remember his Lord is like that between the living and the dead. The remembrance of Allah increases iman and brings peace into the heart. There is none more truthful than Allah in speech and so Allah confirms:
Who have believed and whose hearts have rest in the remembrance of Allah. Verily in the remembrance of Allah do hearts find rest! (Surat ar-Rad 13:28)
Along with praising and glorifying Allah, one should be regular in reciting His
Holy Speech, the Quran, and ponder upon their meanings and use them as a guide and a healing in ones life.
And we reveal of the Quran that which is a healing and a mercy to those who believe(Surat al-Isra 17:82)
The Quran contains the Truth about monotheism, Allahs promises of success to the true believers and warnings of punishment to the hypocrites and disbelievers. It contains commandments and prohibitions, inspiring stories of the previous prophets and their nations, and codes of the best conduct and behavior. The words of the Quran bring hope into a persons life. They enlighten the heart and open up a path of righteousness for those searching for the truth.
Will they not then ponder on the Qur'an? If it had been from other than Allah they would have found therein much incongruity. (Surat an-Nisaa 4:82)
The iman will increase when one connects with Allah through His Holy Revelation and this should lead one to acting upon his Lords Word.
They only are the (true) believers whose hearts feel fear when Allah is mentioned, and when the revelations of Allah are recited unto them they increase their faith, and who trust in their Lord. (Surat Al-Anfaal 8:2)
Remembering the Hereafter is also a cure for weak iman. When one is one hundred percent certain of the Last Day, Paradise, and Hellfire and feels fear of the mere thought of standing before the All-Powerful Creator and be questioned and judged for each of his thoughts, sayings and deeds, he is bound to think twice before committing an act of disobedience. One should remember the Day of Judgement often, which is repeatedly mentioned in the Quran to remind mankind that he will surely be returned to his Lord.
When we look at the night, full of bright glittery stars, the shining moon and the sunset, as well as the mountains standing firm and the flowers blooming, we should feel Allahs Power and Majesty and contemplate over His creation. It is absolutely amazing and unimaginable as to how Allah created every single thing in existence and how the universe runs so smoothly by the will and control of its Creator. Contemplating over the creation is another way a person can increase his iman and grow closer to Allah.
Such as remember Allah, standing, sitting, and reclining, and consider the creation of the heavens and the earth, (and say): Our Lord! You created not this in vain. Glory be to You! Preserve us from the doom of Fire. (Surah Ali Imran 3:191)
Abu Hurairah (radiyallahu anhu) reported that the Prophet (sallallahu alaiyhi wa sallam) said, Allah, the All-Mighty says, I treat my slave according to his expectations from Me and I am with him when he remembers Me. If he remembers Me in his heart, I remember him in My heart. If he remembers Me in a gathering, I remember him in a better and more noble gathering (i.e. of the angels). If he comes close to Me by one span, I go towards him a cubits length. If he comes toward Me a cubits length, I go towards him an arms length. And if he walks toward Me, I run toward him.
One of the most important things a person should be aware of when trying to increase his iman and at all times, is the vastness of Allahs mercy, compassion, and love. One should put hope and trust in Him. Remembrance of Allah is a key factor in increasing the iman, as are increasing ones Islamic knowledge and good deeds. Allah says:
Then, as for those who have faith and do good deeds, He will pay them fully their rewards and give them more out of His grace and as for those who disdain and are proud, He will punish them with a painful doom. And they shall not find for themselves besides Allah any guardian or helper. (Surat an-Nisaa 4:173)
In the following verse, Allah emphasizes the importance of iman and doing good deeds along with ones belief:
There shall be no sin unto those who believe and do good deeds for what they may have eaten (in the past); so be mindful of your duty (to Allah) and do good deeds and again be mindful of your duty and believe and once again, be mindful of your duty and do good deeds. Allah loves the good! (Surat al-Maidah 5:93)
The life of the dunya is only a test for the creation and one day this test will end. It is the responsibility of each human and jinn to prepare oneself for the final scoring of the test by being mindful of ones duty towards Allah by following the guidance of the Quran and the Sunnah and keeping ones iman high. A weak iman will lead one to the Hellfire, while a strong one will lead one to the Gardens of Delight. The reason is because it is the iman that determines the actions of a person. A person with weak or even no iman will commit sin and cause Allah to be displeased, causing him to be thrown into the Hellfire to be punished. But a person with a strong faith will refrain from sins and perform good deeds, which will be the cause of Allahs pleasure and his entrance into Paradise.
In conclusion, Shaykh Muhammad Salih al-Munajjid wrote in his book, Some of our righteous Salaf said, It is a sign of the slaves fiqh (knowledge of the religion) that he concerns himself with enhancing the status of his iman when it experiences a decrease. Also, it is a sign of the slaves fiqh to know if his iman is on the increase or the decrease. Furthermore, it is a sign of ones fiqh that he knows why and where the evil whispers of Satan are coming from.