In the name of Allah, the Beneficent, the Merciful
The most important battle a Muslim needs to fight is the battle within himself against sinful desires (jihad an-nafs). This is a struggle, a jihad in the way of Allah, in which all of us need to participate.
Allah tells us the sinful desires within ourselves must be controlled and submitted to His will, and whoever does so will enter Paradise.
وَأَمَّا مَنْ خَافَ مَقَامَ رَبِّهِ وَنَهَى النَّفْسَ عَنِ الْهَوَىٰ فَإِنَّ الْجَنَّةَ هِيَ الْمَأْوَىٰ
As for him who feared to stand before his Lord and he restrained himself from his desires, then Paradise will be his refuge.
Surat An-Naziat 79:40
For this reason, the Prophet declared that the true mujahid who wages jihad in the cause of Allah is the one who wages jihad against himself.
Fadalah ibn Ubaid reported: The Messenger of Allah, peace and blessings be upon him, said:
الْمُجَاهِدُ مَنْ جَاهَدَ نَفْسَهُ فِي سَبِيلِ اللَّهِ عَزَّ وَجَلَّ
The one who strives in the way of Allah the Exalted is he who strives against his soul.
Source: Musnad Ahmad 23445, Grade: Sahih
Sheikh Al-Mubarakpuri comments on this tradition, saying:
أَيْ قَهَرَ نَفْسَهُ الْأَمَّارَةَ بِالسُّوءِ عَلَى مَا فِيهِ رِضَا اللَّهِ مِنْ فِعْلِ الطَّاعَةِ وَتَجَنُّبِ الْمَعْصِيَةِ ، وَجِهَادُهَا أَصْلُ كُلِّ جِهَادٍ فَإِنَّهُ مَا لَمْ يُجَاهِدْهَا لَمْ يُمْكِنْهُ جِهَادُ الْعَدُوِّ الْخَارِجِ
This means he conquers evil inclinations within himself and performs acts of obedience pleasing to Allah and he avoids acts of disobedience. This jihad is the foundation for all other types of jihad, for indeed, if he does not perform this struggle then he cannot struggle against external enemies.
Source: Sharh Sunan At-Tirmidhi 1621
Allah tells us in several verses that those who purify their hearts from spiritual diseases will enter Paradise. In fact, no one will succeed in the Hereafter unless they approach Allah with a clean heart.
قَدْ أَفْلَحَ مَن زَكَّاهَا وَقَدْ خَابَ مَن دَسَّاهَا
He has succeeded who purifies the soul, and he has failed who corrupts the soul.
Surat Ash-Shams 91:9-10
And Allah said:
يَوْمَ لَا يَنفَعُ مَالٌ وَلَا بَنُونَ إِلَّا مَنْ أَتَى اللَّهَ بِقَلْبٍ سَلِيمٍ
It will be a day when there will be no benefit in wealth or children, but only in one who comes to Allah with a pure heart.
Surat Ash-Shu’ara 26:88-89
This jihad to purify the soul involves struggling against greed for worldly pleasures, hypocrisy and insincerity, hatred and envy, arrogance and pride, vanity and narcissism, and other evil traits which Satan uses to lead us into destruction. Muslims without a doubt needs to make the struggle against these evils their top priority.
Indeed, some of the earliest and most pious scholars among the righteous predecessors (salaf as-salih) considered the jihad against the soul to be the greatest and most important jihad.
Ibn Al-Qayyim reported: It was said to Hasan Al-Basri, “O Abu Sa’eed, which jihad is best?” Hasan, may Allah have mercy on him, said:
Your jihad against your desires.
Source: Rawdat Al-Muhibeen 1/478
Abu Na’eem reported: Ibrahim ibn Adham, may Allah have mercy on him, said:
أَشَدُّ الْجِهَادِ جِهَادُ الْهَوَى مَنْ مَنَعَ نَفْسَهُ هَوَاهَا فَقَدِ اسْتَرَاحَ مِنَ الدُّنْيَا وَبَلَائِهَا وَكَانَ مَحْفُوظًا وَمُعَافًى مِنْ أَذَاهَا
The most difficult jihad is the struggle against desire. Whoever can prevent himself from his desires will be relieved from the world and its trials, and he will be protected and safe from its harms.
Source: Hilyat Al-Awliya 18
Ibn Rajab reported: Ibrahim ibn Abu Alqamah would say to people when they returned from an expedition:
قَدْ جِئْتُمْ مِنَ الْجِهَادِ الْأَصْغَرِ فَمَا فَعَلْتُمْ فِي الْجِهَادِ الْأَكْبَرِ
You have come from the lesser jihad unto the greater jihad.
They said, “What is the greater jihad?” Ibrahim said:
It is the jihad of the heart.
Source: Jami’ Al-Ulum wal-Hikam 19
In fact, the great Caliph Umar ibn Abdul Aziz likewise considered this to be the best and greatest jihad, even though he himself led armies against the enemies of Islam.
Ibn Muflih reported: Umar ibn Abdul Aziz, may Allah have mercy on him, said:
أَفْضَلُ الْجِهَادِ جِهَادُ الْهَوَى
The best jihad is the struggle against desire.
Source: Al-Adab Ash-Shar’iya 131
Thereafter, great scholars of Islam wrote pages and pages about the jihad against the soul and methods of purifying the heart, such as Ibn Al-Jawzi, Ibn Al-Qayyim, and Abu Hamid Al-Ghazali. Scholars often referred to this spiritual struggle as the “greater jihad,” because it takes precedence over any outward physical struggle we endure.
Ibn Taymiyyah said:
جِهَادُ النَّفْسِ وَالْهَوَى أَصْلُ جِهَادِ الْكُفَّارِ وَالْمُنَافِقِينَ فَإِنَّهُ لَا يَقْدِرُ عَلَى جِهَادِهِمْ حَتَّى يُجَاهِدَ نَفْسَهُ وَهَوَاهُ أَوَّلًا حَتَّى يَخْرُجَ إلَيْهِمْ
Jihad of the soul against desire is the foundation of jihad against unbelievers and hypocrites, for a Muslim cannot wage jihad against them unless he has first waged jihad against his soul and desires before he goes out against them.
Source: Rawdat Al-Muhibeen 1/478
Furthermore, armed jihad against an external enemy has conditions and limits and not every Muslim needs to perform it, yet the internal jihad against the soul must be practiced by everyone. A just armed jihad cannot be waged by people whose hearts and minds are defiled by hatred and who are ignorant of Islam’s moral teachings. As such, Allah has commanded the believers to appoint scholars to teach those who perform military service so as to prevent them from transgressing on the battlefield.
وَمَا كَانَ الْمُؤْمِنُونَ لِيَنفِرُوا كَافَّةً ۚ فَلَوْلَا نَفَرَ مِن كُلِّ فِرْقَةٍ مِّنْهُمْ طَائِفَةٌ لِّيَتَفَقَّهُوا فِي الدِّينِ وَلِيُنذِرُوا قَوْمَهُمْ إِذَا رَجَعُوا إِلَيْهِمْ لَعَلَّهُمْ يَحْذَرُونَ
It is not for the believers to go forth in battle all at once. For there should separate from every division of them a group to obtain understanding in the religion and to warn their people when they return to them that they might be cautious.
Surat At-Tawba 9:122
Therefore, the jihad against the soul must be practiced by all of us on a daily basis. We must struggle to purify our hearts from all spiritual diseases that lead to transgression and sin, for only in this way can our external struggles be made just and upright.
Success comes from Allah, and Allah knows best.