In the opinion of the Imams, one of the worst sins among men is enmity and iniquity between themselves. Just as it is said in the Qur'an;
Deem not that Allah is heedless of what the iniquitous do; He is only deferring them to a day when eyes shall stare. (14;42)
Likewise, 'Ali, Amir al-Mu'minin (A.S) had a strong aversion to iniquity, and he told the truth when he said:
I swear by Allah that if all the continents of the earth and all that is under the sun were offered to me in exchange for sinning towards Allah even by stealing a grain of barely from an ant, truly I should never do such a thing.
And this shows how much a person can be aware of the evil iniquity and hold himself back from doing it. 'Ali would not do wrong even to an ant by staling a grain of barely from it, even though all the lands of the earth were offered to him. How then does one stand who sheds the blood of Muslims, plunders their property, and pours scorn on their reputation and honour? How should he be compared with' Ali? Where does he stand compared to the wisdom of' Ali ?Truly, 'Ali's behaviour is
a shining example of the excellent religious education which Islam seeks to instill in humanity.
Iniquity is, then, one of the greatest of the sins Allah has prohibited, and this is why the Household of the prophet have cautioned their followers against it above all else, through their words and prayers. Thus was their policy and behaviour, and they acted justly not only towards their friends, but also towards those who showed disrespect for them and treated them with rudeness.
The story of the forbearance of Imam Hasan (A.S) with the man of Sham (Damascus) who insulted him 9 is well known. On that occasion, the Imam spoke gently with him and treated him kindly, letting him understand that he had done wrong. Even as the fourth Imam, Sayyid as-Sajadin asked for forgiveness for iniquitous persons in his ad'iyyah. This is the utmost generosity and nobility of mind that a perfect man can reach. Although it is correct from an Islamic point of view to avenge an oppressor in one's own manner, and to curse him before Allah, it is better to forgive than to avenge, for forgiveness is a sign of virtue; indeed, in the opinion of the Imams, to curse him is to be iniquitous oneself.
Imam Sadiq (A.S) said:
Verily, a slave is oppressed so long as he refraining from cursing his oppressive master excessively,but if he should do so, then he becomes an oppressor too.
How sublime this is! But if to curse an oppressor is oppression itself, what is the condition of those who instigate oppression and iniquity, who commit aggression against people, or caste aspersions on their reputations, who plunder their property, denounce them before oppressors, or deceive them so that they fall into danger or are hurt, or who spy on them? How do they stand in the wisdom of the Imams? Truly, such persons are the farthest from the generosity of Allah, their sins and their punishment are the most horrible, just as their actions and morality.