In Sufism fear denotes abstaining not only from all that is forbidden but also from those deeds from which it is advisable to refrain. It also signifies as the opposite of hope or expectation that a traveler on the path to Truth does not feel secure against deviation and thereby incurring Divine punishment in the Hereafter. As a result the traveler refrains from conceit and self-praise.

According to Al-Qushayri fear forces a traveler on the spiritual path to hold back and refrain from displeasing God. As such it pertains to the future. Fear arises from one's apprehension of being subjected to something displeasing or uneasiness over not obtaining what is desired. In that sense also fear pertains to the future. In many verses the Qur'an points out the future results of one's deeds and actions and thereby seeks to establish a world embracing the future one in which it is possible to discern the future with both its good and bad elements.

Implanting fear concerning their end or whether they will die as believing Muslims in the hearts of its followers the Qur'an warns them to be steadfast in their belief and practice of Islam. Many verses cause hearts to tremble with fear and are like threads with which to knit the lace of life. For example: Something will appear before them which they had never anticipated (39:47); and Say: Shall We tell you who will be the greatest losers by their works? Those whose efforts have been wasted in the life of the world while they thought they were doing good (18:103-4). How happy and prosperous are those who knit the laces of their lives with these threads! With such warnings the Qur'an orients us toward the Hereafter and encourages us to consider it more important than anything else.

In His luminous Speech. God Almighty uses fear as a whip to force us to His Presence and honor us with His company. Like a mother's reproofs to her child that draws him or her to her warm affectionate arms this whip attracts the believer toward the depths of Divine Mercy and enriches him or her with God's blessings and bounties that He compels humanity to deserve and receive out of His Mercy and Graciousness. For this reason every decree and command mentioned in the Qur'an and forced upon humanity originates in Divine Mercy and uplifts souls in addition to its being alarming and threatening.

One whose heart is full of fear and awe for the Almighty cannot be afraid of others and is therefore freed from all useless and suffocating fear. In His luminous hope-giving Speech the Almighty tells people not to fear anything or anyone other than Him: Have no fear of them. Fear Me if you are true believers (3:175); exhorts them not to suffer groundless phobias: Fear Me alone (2:40) and: They fear their Lord overseeing them from high and they do all that they are commanded (16:50); and praises those hearts that fear and hold only Him in awe: They forsake their beds to cry unto their Lord in fear and hope (32:16).

He praises them because those who design their lives according to their fear of God use their willpower carefully and strive to avoid sins. Such sensitive and careful souls fly in the heavens of God's approval and pleasure. The following is an appropriate saying by the author of Lujja:

If you are fearful of God's wrath be steadfast in religion.
For a tree holds fast to earth with its roots against violent storms.

The lowest degree of fear is that required by belief: Fear Me if you are (true) believers (3:175). A somewhat higher degree of fear is that arising from knowledge or learning: Among His servants the learned alone fear God truly (35:28). The highest degree of fear is that combined with awe and arising from one's knowledge of God: God orders you to fear Him in awe (3:28).

Some Sufis divide fear into two categories: awe and reverence. Although very close in meaning awe connotes the feeling that leads an initiate to flee toward God while reverence causes an initiate to take refuge in Him. An initiate who continuously feels awe thinks of fleeing while one seeking shelter strives to take refuge in Him. Those choosing to flee make progress on the path difficult for themselves for they live an ascetic life and suffer the pains of separation from the Almighty. However those holding Him in reverence drink the sweet enlivening water of nearness which comes from taking refuge in Him.

Perfect reverence was a characteristic of all Prophets. When in this state the Prophets nearly fell down dead as if they had heard the Trumpet of Israfil and were brought before the full Majesty and Grandeur of the Truth. They were always conscious of the meaning of: When His Lord revealed (His) glory to the mountain He sent it crashing down and Moses fell down in a swoon (7:143). Among those brought near to God the one nearest to Him and the master of reverence upon him be peace and blessings said: I see what you do not see and hear what you do not hear. If only you knew that the heavens creaked and groaned. In fact they had to do so for there is no space of even four fingers' breadth in the heavens where angels do not prostrate themselves. I swear by God that if you knew what I know (with respect to God's Grandeur) you would laugh little but weep much. You would avoid lying with your wives and cry out prayers unto God in fields and mountains.

Here the Prophet reveals his reverence that leads him to take refuge in God and describes the awe of others that causes them to flee. Abu Dharr expresses this attitude of fleeing in his addition to this Prophetic Tradition: I wish I had been a tree pulled out by the roots and cut into pieces.

One whose soul is full of reverence and awe of God does not commit sins even if he does not seem to feel fear. Suhayb was one of those overcome with awe of God. God's Messenger upon him be peace and blessings praised him saying: What an excellent servant Suhayb is! Even if he did not fear God he would not commit sins.

One who fears God sometimes sighs and sometimes weeps especially when alone in an attempt to extinguish the pain of being separate from Him as well as the fire of Hell which is the greatest distance between him and God. As stated in the Tradition: A man who weeps for fear of God will not enter Hell until the milk drawn (from a mammal) is put back into the breasts (from which it was drawn) shedding tears is the most effective way of putting out the fires of Hell. A believer sometimes confuses what he or she has done with what he or she has not done and fearing that the action has arisen from his or her fancy or carnal self due to a personal failure to resist temptation feels great regret and seeks refuge in God. The description of such souls is found in the following Tradition:

When the verse: Those who give what they give while their hearts are in awe because they are to return to their Lord (23:60) was revealed. ‘A'isha the Prophet's wife asked the Prophet upon him be peace and blessings: Are those (who are in awe because they are to return to their Lord) those who commit such major sins as fornication theft and drinking alcohol? The Prophet the Glory of Mankind answered: No. ‘A'isha. Those mentioned in the verse are those who although they perform the prescribed prayers fast and give alms tremble with fear that such acts of worship may not be accepted by God.

Abu Sulayman Darani says that although a servant must always be fearful (that God may not be pleased and therefore punish him or her) and hopeful (that God may be pleased) it is safer for one's heart to beat with fear and reverence. Sharing the view of Darani. Shaykh Ghalib expresses his feelings of fear: Open the eyes of my soul with a thousand-fold fear!