Self is our biggest and most staunch enemy who is permanently and continuously at war with reason; by listening to Satanic whispers he attacks the reason together with his soldiers to get it isolated and ultimately silenced, so that he becomes the sole-contender in the battle-field. His single goal is to force out God's favorite angels from the heart's kingdom and helping Satan to take over his absolute control. Naturally, defeating such a treacherous enemy is not on easy task, but requires determination, resistance, perseverance, and even crusade -a crusade not only for once or twice, for a few days and few years but continuous one till the last breath of life, which is a hard, difficult, and serious struggle.
In order to defeat the self and to control passions we must fight hard by strictly following the commands of Prophet (S) and Infallible Imams (A); with the help of reason must march forward preventing transgressions and encroachment of the self, and destroying the roots of his forces, so that reason could take over the power, and by taking inspirations from religious law could guide us upon the path of human perfection leading towards God's-Nearness.
We must know while confronting self, compromise and piece settlement is not possible, and what is required is a devastating blow making him crippled permanently from plotting any further conspiracies. In order to achieve happiness and salvation there is no other alternative except to follow this course, and because, of this reason struggle against the self has been called in traditions as -"Greater-Crusade" (Jihad-e-Akbar). Here we would quote few examples from the Commander of the Faithful Imam' Ali (A):
"Take over the possession of yourself--through continuous struggle.”
-Ghararal-Hukm, vol. l, p-131.
”Fight and dominate over self’s whims and passions. Because otherwise if they succeeded in making you their prisoner -they will treat you in a most humiliating manner destroying you eventually. -Gharar al-Hukm, vol. 1, p-138.
"Be aware! That Paradise is purchased through self-struggle. Therefore, who is engaged in self -struggle will be victorious. Paradise (or self) is the greatest reward for some one who really appreciates their worth." -Gharar al-Hukm, vol. 1, p-165.
"By means of fighting against the self; incite him towards God's worshipping. Fight him the way one must fight with his worst enemy, and dominate over him like the domination of victor over his opponent. The most powerful person is the one who is victorious over his self " -Gharar al-Hukm, vol. 1, p-371.
"A wise man keeps himself engaged in struggle against his self, thus, reforming and preventing him from indulging into passions and amusements, and in this manner subdues him ultimately taking over his possession. Such a wise person is so must preoccupied in his self-refinement that he is totally detached with the world, whatever it contains and its dwellers." -Gharar al-Hukm, vol. 1, p-237.
Struggle against the self is the most crucial warfare which ultimately determines our destiny -a warfare upon which depends our ‘how to live’ in this world and the Hereafter. If, we do not dominate the self through struggle and take over the ruling authority in our own hands, he will take over the control of our possessions by pulling us in every direction at his will. If, we failed to make him our prisoner, he will certainly take us into his imprisonment as his slaves; if we could not succeed in inciting him for doing good moral virtuous deeds, he will force us to indulge into most shameful evil deeds. Therefore, it must be said that the struggle against the self is one of the most important and difficult duty which has been assigned upon the shoulders of the wayfarers journeying towards God, and whatever energy is spent by them in this struggle deserves merit and is energy well spent.
7.1. Greater Struggle (Jihad-e-Akbar)
The struggle against the self is so important that the Prophet (S) has described it as the "Greater-Struggle" (Jihad-e-Akbar); It is so crucial that it has been described, even greater than the armed conflict. The Commander of the Faithful Imam 'Ali (A). had narrated:
"That the Prophet (S) dispatched his soldiers to battle front to fight against the enemy. When the soldiers returned triumphant, the Prophet said: ' Congratulations! For those who have successfully completed the "Minor-Struggle " (Jihad-e-Asghar), but they have yet to engage themselves into Greater-Struggle (Jihad-e-Akbar) '. He was asked: 'Oh Prophet of God! What is the Greater- Struggle?”
'Struggle against the self.’ Replied the Prophet (S).”
-Wasail al-Shia, vol. 2, p-124.
The Commander of the Faithful Imam 'Ali (A) said:
"The best crusade is the, struggle of some one, who fights' against his self located between his two sides."
-Ghararal-Hukm, vol. 11, p-124.
In his death will the Prophet (S) said to Imam 'Ali (A):
“Oh Ali! The best struggle is the struggle of some one who made his night into morning without thinking to oppress a single individual.”
-Wasail al-Shi'a, vol. 11, p-123.
In these traditions the importance of struggle against the self have been described as "Greater-Struggle" or Supreme Crusade -the crusade which is even superior than the crusade for the sake of God-Almighty (Jihad fi Sabil illah). Considering the exalted position of crusade for the sake of God, which is considered as one of the most superior worshipping -the importance and worth of self-struggle becomes explicitly clear. In order to further explain its superiority in detail we may point out the following three reasons:
7.1.A. First Reason
Each act of worship even armed struggle required self-struggle from the following two considerations.
(i) Firstly: The performance of each act of worship with perfection and in accordance with certain requirements itself requires self-struggle.
Is the performance of daily prayer  with presence of mind as well as meeting all other conditions, so that it indeed becomes -a believers heavenly journey preventing him from fortifications and forbidden deeds -possible without efforts and self-struggle?
Is fasting with perfection satisfying all its requirements so that it becomes -a shield against Hell's fire -possible without self-struggle? Is it possible for a valiant, crusader eager for martyrdom, to appear on the battle field to fight bravely with the enemies of Islam without self-struggle? And similar is applicable to all other worships.
(ii) Secondly: Every act of worship is accepted by God-Almighty and becomes a means of attaining His Nearness, subjected to its being performed solely for the sake of His Pleasure, being purified from ,all traces of polytheism, self-deceit and other selfish passions, and performance of such acts without self-struggle are not possible. Even the armed struggle and martyrdom are worthy of merit and become means of attaining God's Nearness -only if they are performed purely for the sake of God’s Pleasure and declaration of slogan of Monotheism (Towheed).
But, if this superior worship was performed with the intention of achieving fame and glory: .taking revenge from the enemy, for the sake of lasting the name in history, for showing off and deceit, for achieving wealth and position, running away from facing life's difficulties, and other desires of the self -then in that case they lack any spiritual distinction and do not become means of attaining God's Nearness. Therefore, self-struggle is superior then all worships and virtuous deeds, even armed struggle undertaken for the sake of God-Almighty, because, it is a prerequisite for their genuine dischargement with perfection. It is because of these considerations that this has been called as the -Greater-Struggle (Jihad-e-Akbar).
7.1.8. Second Reason
Armed struggle becomes compulsory only under certain special times and circumstances, further it is not incumbent upon everyone (Wajib-e-aini), rather is a collective obligation (Wajib-e-kifai), and some people are free from this obligation. During certain periods armed struggle is not required at all, or is required to the extent of collective obligation, e.g. if required number of people had assumed this obligation, then the others are excused. Apart from this it is not incumbent upon women, elderly men, handicapped, and sick people. But on the contrary, struggle against the self is incumbent upon everyone as an individual obligation (Wajib-e-aini) during all times, circumstances, and situations, must be continued till the very last moments of life, and no body under any condition except the impeccable (Masoomin) (A) will ever be free this requirement.
7.1.C. Third Reason
The struggle with self is harder than all the worships even the armed struggle in which a combatant risks his life by accepting martyrdom. Because, absolute surrender before God-Almighty, self-struggle against self's whims and passions for the entire life, and journeying towards the straight path of perfection is much more difficult than the fighting of a valiant warrior with the enemy in the battle field for a moment and ultimately achieving martyrdom. In fact, self-struggle is so hard that except with continuous resistance, tolerance of pains and anguishes, and without God's Assistance it is not possible. It is because of this reason that we recite five times every day in daily prayers the sentence:
"Show us the straight path” 
To follow up the straight path of perfection is so difficult that the Prophet of Islam (S) said to God-Almighty:
"Oh God! Don't leave me at the disposal of myself even for the fraction of a second."
7.2. Struggle and Divine Assistance
True, that self-struggle is extremely difficult, requires resistance, perseverance, and intelligence, but any how it is possible and is something absolutely necessary for human happiness. Therefore, if one decides seriously to begin it, he will certainly receive Divine Assistance and will succeed in his efforts.
As God-Almighty has promised in the Quran:
"And those who strive in our cause -we will certainly guide them to our paths. For verily God is with those who do right.”
-the Holy Quran (29:69)
Imam al-Sadiq (A) said:
"How good is a servant of God who struggles against the self and his passions for the sake of God's Pleasure. Whoever becomes victorious over the self’s whims and passions has already achieved God's-Pleasure. Whoever offers resistance, and with humility in front of God, allows the reason to control imperious-self would receive the greatest blessing.”
"There exists between the servants of God and Him nothing darker and horrible barrier than the imperious-self and his passions, and in order to destroy their roots forever, the realization to seek God, humility, hunger, thirst during the day (i. e. fasting), and night awakening (i.e. engaging in night prayers and having humming communications with God-Almighty). Such a person if dies in this course has left the world as a martyr, and if remains alive would ultimately attain the exalted position of God's Nearness. God-Almighty has promised in the Holy Quran that those who strive in His cause will certainly be guided towards His path and verily, God is with those who do right.”
"When you encounter another struggler endeavoring in self-refinement better than your own efforts, then reprimand your self severely, and , remind him to be more careful and determined. In accordance with Divine do's and don'ts make a bridle for the self and like a master, training his inexperienced and wanton slave, encourage your self towards virtuous deeds. The Prophet (S) offered so much prayer that his feet become swelled, in response to people' s complaint, replied: should not I be thankful to God-Almighty ?”
"By these serious endeavors in worship the prophet (S) wanted to teach a lesson to his community. Therefore, one should never be negligent from endeavors, worship, and ascestism. Know that! if you could witness the sweetness of worshipping and other blessings and if your heart becomes illuminated with Divine Light -you will not be ready to discontinue if for an hour, even if they cut off your body into several pieces. Therefore, the negligence from worshipping shall never be possible except being deprived from advantages of competing for achieving immunity against sins and attaining God's -Blessings."
-Bihar al-Anwar, vol. 70, p-69.
Self struggle is exactly like the armed struggle. Each blow inflicted upon the enemy, and every stronghold captured by means of soldiers make the enemy weaker in the same proportion, thus, making the, forces psychologically stronger and better prepared for subsequent assaults and later victories. It is in accordance of this Divine Tradition that we are told in the Holy Quran:
"Oh ye who believe! If you help God's cause, He will make your foothold firm.”
-the Holy Quran (47:7)
The same is true with self-struggle. Each blow inflicted upon imperious-self and his whims and passions being opposed, makes him weaker in the same proportion and, thus, making us stronger and better prepared for subsequent assaults and later victories. But opposite to that any amount of irresolution shown and surrender to self's whims and passions make us weaker and making him stronger and better equipped for later assaults. If we could take the first giant step towards self-refinement, then with Divine Assistance will be able to achieve absolute domination over the self, but if we ran away from the battle field against the passions and self's soldiers, then they will become more stronger and ultimately take over our absolute control.
7.3. Man -His own Physician
It is true that Prophets and Infallible Imams (A) are the teachers and physicians of human souls, but the responsibility for treatment, refinement, and purification of their souls have been assigned upon their own shoulders. Although, the Prophets and Infallible Imams (A) have lectured and explained to human beings in details about their psychic diseases and symptoms, issued relevant prescriptions for their treatments, so that they could become familiar with their pains and treatments, and could assume the responsibility of their own self reforms.
Because, nobody could diagnose the disease and take the necessary action for its treatment, better than the man himself. Man listens about the psychic disease and their treatments either from the tongue of a preacher, or learns through reading a book, but the one who must discover the disease with in his own-self, and should use a particular medicine for its treatment -is no body except man himself. A man could feel about his own pains, and is knowledgeable about the hidden mysteries within, far better than anyone else. Therefore, if he himself is not careful in controlling his own-self, then of course, the preaching and warning issued by others would not produce any useful outcome.
Islam believes that reforms must begin from the inner existence of human beings, they must be prepared for undertaking self-refinement, should pay attention to psychological hygiene, and should be assigned the responsibility to guard their own souls. This in itself could be considered as one of the important principle of Islamic training. The God-Almighty, said in the Holy Quran:
"Oh, but man is telling witness against himself, although he tender his excuses.”
-the Holy Quran (75:14-15)
Imam al-Sadiq (A) said:
"You have been appointed physicians of your own self pains, prescriptions, and symptoms of sound health all have been explained for you; now let us see, how are you going to act for the treatment of your self?”
-al-Kafi, vol. 2, p-454.
"Whoever does not have a preacher within his own-self, preaching by others, will not be of any use for him."
-Bihar al-Anwar, vol. 70, p-70.
Imam al-Sajjad (A) said:
“Oh son of Adam! So for as you have a preacher inside your self -you are bound to do good deeds."
-Bihar al-Anwar, vol. 70, p-64.
The Commander of the Faithful Imam 'Ali (A) said:
"The most helpless person is the one-- who is helpless in reforming his self."
-Gharar al-Hukm, vol. 1, p-196.
"It is desirable that a man should assume the responsibility of supervision over his own-self He should continuously watch out his heart and control his tongue."
-Gharar al-Hukm, vol. 2, p-862.
 Daily prayer: the Prophet (S) has called the prayer: the ladder of a believer carrying him higher towards the heavens. Also, God-Almighty said in the Holy Quran:
“For prayer restrains from shameful and unjust deeds.” -the Holy Quran (29: 45) [Tr].
 “If a man could have a superior and more vital aim than the "guidance", certainly that would have been included in the Surah Praise -a Surah which is the Opening Chapter of the Holy Quran and forms an important part of the prayer , and it would have been recited as a prayer for acceptance from God. It is by way of His direction or guidance that the intellect and experience set their course in the correct, advantageous, and suitable position widening the path of a wayfarer. Otherwise, without it, the intellect and experience would turn into alight in the hands of a thief, or a piece of sharp blade in the hand of a mad man." -Profundities of Prayer, Sayyid Ali Khamenei, p-33 [Tr]