One of the most momentous tasks for which the Prophet, , was sent was the purification of souls, as Allah The Almighty Says (what means): {It is He Who has sent among the unlettered a Messenger from themselves reciting to them His verses and purifying them and teaching them the Book and wisdom - although they were before in clear error.} [Quran 62:2]

　　Thus, He has also made success dependant on the cleansing of the self; after swearing eleven times successively, Allah The Almighty affirms, Saying (what means): {He has succeeded who purifies it,* And he has failed who instills it [with corruption].} [Quran 91:9-10]

　　Undoubtedly, one of the most crucial ways of achieving this purification is to nurture the soul to fear Allah The Almighty. Imaam Ibn ul-Qayyim said, "The degree of fear is one of the degrees of [servitude implied in the verse (which means)], "It is You we worship and You we ask for help". In fact, it is of the most magnificent ranks on the way to [worshipping] Allah, and the most useful for one’s heart. Thus, it is obligatory on everyone."

　　He added, "The heart, on its path to Allah The Almighty, is like a bird; its head is love and its wings are fear and hope. When these are all sound, the bird flies well. But, were the head to be cut off, [it] would die; and if the two wings are missing, the bird becomes a vulnerable prey for predators and hunters."

　　When fear inhabits the heart, it eats away the black spots of desires, expelling [love of] the worldly life from it. That is because it is the device of Allah The Almighty with which He disciplines those who are away from Him and drives them away from Hell and severe punishment. That is why Al-Fudhayl would declare, "Anyone who fears Allah will be guided by [that attribute] to all good things."

　　Conversely, when fear deserts the heart, it is ruined, to the extent that one begins to dare to commit sins. But, how could a servant not fear Allah The Almighty in this world, when he or she knows of the grave terrors to come, for the manner in which his or her life will end is a tossup? Sahl said, "The steadfast affirmers of truth fear having an abominable demise, with every thought and movement. Allah The Almighty Says about them (what means): {Their hearts are fearful.} [Quran 23:60]”

　　When the pious man, Sufyaan Ath-Thawri was about to die, he wept profusely; so, it was said to him, "Be hopeful, for the forgiveness of Allah is greater than your sins." He responded, "Do I cry for the sins I have committed? If I know that I will surely die as a monotheistic Muslim, I will not be afraid of meeting Allah with sins as huge as mountains."

　　Indeed, when a deceased man is buried and then questioned by the two angels in the grave, he does not know whether he will be steadfast or not. That is why, the Prophet, , once sat next to the edge of a grave and cried; he then cautioned: "O brothers, prepare for [your day like] this."

　　If a person reflects on the terrors of the gathering of people in the Hereafter, the scale that will be used to measure our deeds, the bridge over Hell and the movement of people toward Paradise or Hell, his or her heart will be overwhelmed with fear. Consequently, that will prevent him or her from committing a lot of unlawful acts.

　　However, while fearing something causes one to flee from it, fearing Allah The Almighty makes one actually run to Him, as He Says (what means): {So flee to Allah. Indeed, I am to you from Him a clear warner.} [Quran 51:50]

　　Levels of fear

　　Some scholars have mentioned that fear has many levels, such as:

　　(1) Fear of prevention from seeing Allah The Almighty: This is the most sublime level; it is the fear of the knowledgeable. The more a servant is aware of Allah The Almighty and His attributes, the more he fears Him, as He Says (what means): {Only those fear Allah, from among His servants, who have knowledge.} [Quran 35:28]

　　Therefore, the Prophet, , was the most fearful person of all, as he is reported to have said about himself: "Indeed, I am the most knowledgeable of you about Allah and the most fearful of Him amongst you." When it was said to him: "O Messenger of Allah, you have aged”, he replied, "(The chapter) Hoode and its counterparts have turned my hair white."

　　In another categorization of fear, some scholars posited that it may be characterized as deficient, excessive or moderate, with the latter being praiseworthy. That is because, in this case, it urges one to perform obligations and abandon prohibitions. If it further intensifies to the point that it drives him or her to increase in worship, and abstain from even minor bad deeds and from overindulgence in what is permitted [as opposed to what is rewardable], then it is better.

　　In contrast, the deficient type of fear is like mood swings; it appears when something activates it, like listening to a Quranic verse, admonition or something else; so, one sheds tears then and his or her heart becomes fearful. But, when the trigger no longer exists, that person returns to his or her state of heedlessness. This is the inadequate fear that hardly bears fruit.

　　Finally, the excessive fear is that which causes despair, illness or distress, to the extent that it makes one stop seeking virtues that are liked by Allah The Almighty; of course, this is dispraised.

　　May Allah The Almighty help us fear Him in secret and in public.