Imam Kazim (peace be upon him): Muhammad ibn Abi Umayr said: I heard Imam Kazim (peace be upon him) saying: "Allah does not keep anyone in the Fire forever except the people of disbelief and denial, and the people of misguidance and polytheism. And a believer who has shunned the major sins is not questioned about his minor sins, for Allah has said: إِنْ تَجْتَنِبُوا کَبائِرَ ما تُنْهَوْنَ عَنْهُ نُکَفِّرْ عَنْکُمْ سَیِّئاتِکُمْ وَ نُدْخِلْکُمْ مُدْخَلًا کَرِیماً [If you shun the great sins which you are forbidden, We will do away with your small sins and cause you to enter an honorable place of entering]." I asked the Imam (peace be upon him): "O son of the Messenger of Allah (peace be upon him and his family), for which of the believers does intercession become obligatory and necessary?" He said: "My father narrated from his fathers from Imam Ali (peace be upon him) who said: I heard the Messenger of Allah (peace be upon him and his family) say: 'Those of my Ummah who have committed major sins become in need of my intercession, and the righteous among them have no other way [to be delivered from the Fire].'" I said to the Imam (peace be upon him): "O son of the Messenger of Allah (peace be upon him and his family), how does your intercession include the people of major sins, when Allah says: 'And they do not intercede except for one whom He approves, and they are, from fear of Him, in awe.' (al-Anbiya/28). And certainly one who commits a major sin is not one whom Allah is pleased with." The Imam (peace be upon him) said: "O Aba Ahmad, there is no believer who commits a sin but that he regards it as ugly and repents of it. And the Prophet (peace be upon him and his family) has said: 'It is enough for you to be considered as having repented that you are regretful.' And he said: 'Whoever is made happy by his good deeds and grieved by his evil deeds is a believer, and whoever does not regret a sin he has committed is not a believer, and our intercession does not reach him, and he is counted a wrongdoer. And Allah said: The wrongdoers on that Day will have no close friend nor any intercessor whose word will be heeded. (Ghafir/18).'" I said: "O son of the Messenger of Allah (peace be upon him and his family), why is a person who has not regretted his sin not a believer?" The Imam (peace be upon him) said: "O Aba Ahmad, there is no one who commits a major sin and knows that he will be punished for committing it but that he regrets what he has done. And whenever he regrets, it is as though he has repented and is deserving of intercession. But if he does not regret, it means he persists in committing it, and one who persists in a major sin is not forgiven, because he does not believe in the punishment for what he has done. For had he believed in the punishment for his deed, he would certainly have regretted." The Prophet (peace be upon him and his family) said: "No sin is counted major when istighfar (seeking forgiveness) is made, and no sin is minor when it is persisted in. And the word of Allah, that He said: 'And they do not intercede except for one whom He approves.' (al-Anbiya/28), what is meant is that the intercession of those is accepted whose religion Allah is pleased with. And by 'religion' is meant faith itself and the acknowledgment that good and evil deeds have reward and punishment. And whoever Allah is pleased with in his religion and belief regrets the sin he has committed, because he knows and recognises the end and recompense of his deed in the Hereafter."