Al-Imam Ali (p.b.u.h), said:
31. Faith, Unbelief, Doubt And Their Supports
Amir al-mu’minin, peace be upon him, was asked about faith. He said:
Faith stands on four supports: on endurance, conviction, justice, and jihad (fighting in the way of Allah).
Endurance again has four aspects: eagerness, fear, abstention (from the world), and anticipation (of death). So, whoever is eager for Paradise will ignore the passions; whoever fears the Fire (of Hell) will refrain from prohibited acts; whoever abstains from the world takes hardships lightly; and whoever anticipates death will hasten towards good deeds.
Conviction also has four aspects: prudent perception, intelligence and understanding, drawing lessons from instructive things, and following the precedents of past people. So, whoever perceives with prudence, wise knowledge will be manifest to him, and to whomsoever wise knowledge becomes manifest he appreciates instructive objects, and whoever appreciates instructive objects is just like past people.
Justice also has four aspects: keen understanding, deep knowledge, a good power of decision, and firm forbearance. Therefore, whoever understands comes to acquire depth of knowledge; whoever acquires depth of knowledge drinks from the spring of judgment; and whoever exercises forbearance never commits evil actions in his affairs and leads a praiseworthy life among the people.
Jihad also has four aspects: to ask others to do good, to keep away others from doing evil, to fight (in the way of Allah) sincerely and firmly on all occasions, and to detest the vicious. So, whoever asks others to do good provides strength to the believers; whoever desists others from evil humiliates the unbelievers; whoever fights sincerely on all occasions discharges all his obligations; and whoever detests the vicious and becomes angry for the sake of Allah, then Allah will be angry in favor of him and will keep him pleased on the Day of Judgment.
Unbelief stands on four supports: hankering after whims, mutual quarrelling, deviation from the truth, and dissension. So, whoever hankers after whims does not incline towards right: whoever quarrels much on account of ignorance remains permanently blinded from the right; whoever deviates from truth, for him good becomes evil and evil becomes good, and he remains intoxicated with misguidance; and whoever makes a breach (with Allah and His Messenger), his path becomes difficult, his affairs become complicated, and his way of escape becomes narrow.
Doubt has also four aspects: unreasonableness, fear, wavering, and undue submission to everything. So, he who adopts unreasonableness as his way, for him there is no dawn after the night; he who is afraid of what befalls him has to run on his heels; he who wavers in doubt, Satans trample him under their feet; and he who submits to the destruction of this and the next world succumbs to it.
As-Sayyid ar-Radi says: We have left out the remaining portion of this saying for fear of length and for being outside the purpose of this chapter.
Source: https://www.al-islam.org/nahjul-balagha-part-2-letters-and-sayings
