How can we fear Allah, may He be glorified and exalted?
Question

                Please advise me how I can fear Allah, the Compeller, the Most Gracious, may He be exalted; I am lost!
Praise be to Allah.Firstly:
Fear of Allah, may He be exalted, is obligatory for everyone, and no one can be guaranteed safety from Allah’s punishment except by fearing Him. Allah, may He be glorified and exalted, says (interpretation of the meaning):
“so fear them not, but fear Me, if you are (true) believers”
[Aal ‘Imraan 3:175]
“Therefore fear not men but fear Me”
[al-Maa’idah 5:44]
“and fear none but Me”
[al-Baqarah 2:40].
The Prophet (blessings and peace of Allah be upon him) said: “Allah, may He be glorified and exalted, says: ‘By My might, I will not let My slave suffer from fear in two realms or feel safe in two realms. If he feels safe from Me in this world, I will make him feel fear on the Day of Resurrection, but if he fears Me in this world, I will make him feel safe on the Day of Resurrection.’”
Narrated by Ibn al-Mubaarak ibn az-Zuhd (157); classed as saheeh by al-Albaani in as-Saheehah (742).
Secondly:
How can we fear Allah, may He be glorified and exalted? What must we do in order to attain this status?
How can one who loves Allah, may He be exalted, develop fear of Him?
There are Islamically prescribed means of attaining that, and deeds of the heart that lead to it, of which we will mention whatever we are able to, in sha Allah, so that every Muslim who reads them may develop fear of his Lord and fear of His punishment, and his fear may lead him to think positively of Allah, may He be glorified. These means include the following:
· Reading Qur’an and reflecting on its meanings
Allah, may He be exalted, says (interpretation of the meaning):
“Say (O Muhammad (blessings and peace of Allah be upon him) to them): ‘Believe in it (the Quran) or do not believe (in it). Verily! Those who were given knowledge before it (the Jews and the Christians like Abdullah bin Salam and Salman Al-Farisee), when it is recited to them, fall down on their faces in humble prostration.’
And they say: ‘Glory be to our Lord! Truly, the Promise of our Lord must be fulfilled.’
And they fall down on their faces weeping and it adds to their humility”
[al-Isra’ 17:107-109]
“Those were they unto whom Allah bestowed His Grace from among the Prophets, of the offspring of Adam, and of those whom We carried (in the ship) with Nooh (Noah), and of the offspring of Ibrahim (Abraham) and Israel and from among those whom We guided and chose. When the Verses of the Most Beneficent (Allah) were recited unto them, they fell down prostrating and weeping”
[Maryam 19:58].
· Calling to mind how serious and terrifying the matter of sin is
Al-Bukhaari (6308) narrated that Ibn Mas‘ood (may Allah be pleased with him) said: “The believer regards his sins as if he is sitting beneath a mountain that he fears will fall on him, and the evildoer regards his sins as flies that pass in front of his nose and he does like this to them [waving them away with his hand].”
· Fearing Allah, may He be exalted, by doing acts of obedience and worship, and refraining from evil deeds and prohibited things
This will instil fear in the heart and revive hearts after they had been (spiritually) dead; it will fill them with love of Allah, the desire to seek His pleasure, and fear of His wrath.
· Respecting the sacred limits of Allah
Ibn al-Qayyim (may Allah have mercy on him) said:
The level of fear that is praiseworthy and appropriate is that which prevents a person from transgressing the sacred limits of Allah, may He be glorified and exalted; if the fear passes that limit, there is the risk that it will led to despair and despondency.
Abu ‘Uthmaan said: True fear is that which makes a person refrain from sins both outward and inward.
I heard Shaykh al-Islam Ibn Taymiyah (may Allah sanctify his soul) say: Praiseworthy fear is that which keeps you from transgressing the sacred limits of Allah.
End quote from Madaarij as-Saalikeen (1/510)
· Knowing Allah, may He be glorified and exalted, by His names and attributes
Ibn al-Qayyim (may Allah have mercy on him) said:
The more a person knows of Allah, the more he will fear Him. Ibn Mas‘ood (may Allah be pleased with him) said: Fear of Allah is sufficient indication of knowledge. Lack of fear of Allah is due to a person’s lack of knowledge of Him. The most knowledgeable of people are those who fear Allah the most. If a person knows Allah, he will feel more shy before Him, will fear Him more and love Him more. The more his knowledge increases, the more his shyness, fear and love of Him increase.
End quote from Tareeq al-Hijratayn (p. 283)
· Knowing the virtue of those whose hearts are filled with awe of  Allah
Allah, may He be exalted, says (interpretation of the meaning):
“The believers are only those who, when Allah is mentioned, feel a fear in their hearts and when His Verses (this Qur’an) are recited unto them, they (i.e. the Verses) increase their Faith; and they put their trust in their Lord (Alone)”
[al-Anfaal 8:2].
It was narrated that Abu Hurayrah (may Allah be pleased with him) said: The Messenger of Allah (blessings and peace of Allah be upon him) said:
“No man who wept for fear of Allah will enter the Fire until the milk goes back into the udder, and the dust (raised when fighting) for the sake of Allah and the smoke of Hell will never be combined (in the nostrils of any man).”
Narrated by at-Tirmidhi (1633) and an-Nasaa’i (3108). Classed as saheeh by al-Albaani.
And it was narrated from him that he said: The Messenger of Allah (blessings and peace of Allah be upon him) said: “There are seven whom Allah will shade with His shade on the Day when there will be no shade but His… and a man who remembers Allah when he is alone and his eyes fill with tears.”
Narrated by al-Bukhaari (660) and Muslim (1031).
· Pondering the stories of those who feared Allah and how they reached this status by means of faith and righteous deeds, praying qiyaam at night and fasting by day, and weeping for fear of Allah
Al-Ghazaali (may Allah have mercy on him) said:
Studying and learning the biographies of the Prophets and the Sahaabah it is a means of instilling fear of Allah, for if one is not affected immediately, one will be affected later on.
End quote from Ihya’ ‘Uloom ad-Deen (2/237)
Ibn al-Jawzi (may Allah have mercy on him) said:
Knowing the greatness of Allah will increase one’s fear of Him, and whoever fears the punishment of his Lord will do good deeds. So fear of Allah removes the disease of idleness and heals it. It is the best discipline for the believer and is sufficient for him.
Al-Hasan said: I have accompanied some people who were more afraid of their good deeds being rejected than of being punished for their bad deeds…
End quote from Mawaa‘iz Ibn al-Jawzi (p. 91).
· Reflecting upon the verses that speak of punishment and warnings, descriptions of Hell and the condition of its inhabitants, and what they will suffer of eternal misery, wretchedness and torment
· Knowing your real situation
and remembering that you are weak and insignificant; if Allah so willed He could hasten the punishment for you. So one who is like this should fear his Lord. Al-Ghazaali (may Allah have mercy on him) said:
Fear of Allah, may He be exalted, may be the result of knowing Allah, may He be exalted, and knowing His attributes, and that if He wanted to destroy all of creation, He could do so, and no one could prevent Him from doing that. Or it may be due to one’s committing sins. And it may be both, and the more a person is aware of his own faults and the more He recognises the majesty of Allah, may He be exalted, and that He is completely self-sufficient, the more he will fear Him. The one who fears his Lord the most is the one who knows himself and his Lord best.
End quote from Ihya’ ‘Uloom ad-Deen (4/155).
· Reflecting upon the stories of the wrongdoers and sinners whom Allah punished for their sins
What became of them? What is their situation now, after the punishment came upon them? Allah, may He be exalted, says (interpretation of the meaning):
“And how many a generation before them have We destroyed! Can you (O Muhammad (blessings and peace of Allah be upon him)) find a single one of them or hear even a whisper of them?”
[Maryam 19:98].
· Reflecting upon the condition of the people on the Day of the greatest fear and the great distress that they will feel
Allah, may He be exalted, says (interpretation of the meaning):
“O mankind! Fear your Lord and be dutiful to Him! Verily, the earthquake of the Hour (of Judgement) is a terrible thing.
The Day you shall see it, every nursing mother will forget her nursling, and every pregnant one will drop her load, and you shall see mankind as in a drunken state, yet they will not be drunken, but severe will be the Torment of Allah”
[al-Hajj 22:1-2]
“Indeed in that (there) is a sure lesson for those who fear the torment of the Hereafter. That is a Day whereon mankind will be gathered together, and that is a Day when all (the dwellers of the heavens and the earth) will be present”
[Hood 11:103]. 
· Listening to moving exhortations and heart-stirring lectures
It was narrated that al-‘Irbaad ibn Saariyah (may Allah be pleased with him) – who was one of those who wept a great deal – said: The Messenger of Allah (blessings and peace of Allah be upon him) delivered an eloquent exhortation which caused eyes to flow with tears and hearts to tremble with fear. 
Narrated by at-Tirmidhi (2676); Abu Dawood (4607); Ibn Maajah (42). Classed as saheeh by al-Albaani. 
· Remembering Allah a great deal
Remembering Allah a great deal motivates one to constantly bear in mind the majesty and greatness of Allah, to remember that He is always watching, to love Him and feel shy before Him. All of that instills fear of Allah and of His Punishment, and fear of being deprived of Paradise. 
· Fearing sudden of punishment and not being given respite to allow repentance
Ibn al-Qayyim (may Allah have mercy on him) said: 
Fear (of Allah) stems from three things: 
1. Being aware of one’s offence and how abhorrent it is
2. Believing the warning, and that Allah has prescribed the punishment for the sin.
3. Remembering that one does not know: perhaps one will be prevented from repenting, and something may bar one from doing so if one commits the sin.
By means of these three things, fear of Allah will be instilled, and depending on how strong or weak they are, one’s fear of Allah will be stronger or weaker. What pushes a person to commit sin is either his lack of knowledge of its abhorrent nature, or his lack of knowledge of its evil consequences, or both factors are present, but what pushes him to do it is the fact that he is relying on the idea of repenting (at some future time). This is usually the case with regard to sins committed by believers. But if a person is aware of the abhorrent nature of the sin and of its evil consequences, and he is afraid that the gate of repentance may not be opened to him – rather he may be prevented from repenting – then his fear will be greater. 
This applies before committing the sin. If he does commit it, then his fear will be even greater. To sum up, if a person constantly remembers the hereafter and its requital, and he remembers sin and the warning of punishment for it, and that there is no guarantee that he will be able to repent sincerely, then this will instil fear in his heart that he will have no control over, and this fear will remain in his heart until he is safe. 
End quote from Tareeq al-Hijratayn (p. 283) 
For more information, please see the answers to questions no. 46911, 104771 and 125618 
And Allah knows best.