When Amir al-Mu'mineen 'Ali (Radhi Allahu Anhu) was asked about
faith, he said:
"Faith is based on four pillars: patience, certainty, justice and striving.
Patience is based on four things: longing, fear, asceticism and expecting death. The one who longs for paradise will be able to turn away from physical desires, the one who fears hellfire will avoid Haram things, the one who has no interest in worldly gains will not be distressed by calamities, and the one who expects death will hasten to do good things.
Certainty is based on four things: deep insight, wisdom, learning lessons from others and the ways of those who came before. Whoever has deep insight will have wisdom, and whoever has wisdom will learn the lesson; the one who learns the lesson will be as if he was among those who came before.
Justice is based on four things: deep understanding, deep knowledge, proper judgement and patient forbearance. Whoever understands will gain deep knowledge, whoever gains deep knowledge will have proper judgement, and whoever has forbearance will not go to extremes and will be well liked by people.
Striving is based on four things: enjoining what is good, forbidding what is evil, taking a sincere stance in different situations and resenting evildoers. The one who enjoins what is good will support the believers; the one who forbids what is evil will annoy the hypocrites; the one who takes a sincere stance in all situations has done what is required of him; and the one who resents the evildoers and gets angry for the sake of Allah, Allah will get angry for his sake and will make him content on the Day of Resurrection.
Source: Ali ibn Abi Talib (Radhi Allahu Anhu) – Dr Ali M Sallabi Pages 425-426