Says the Shaykh Abu Ja'far, the mercy of Allah on him: We believe that shafa'a1 (here, the state of being forgiven) belongs to him whose religion is approved (by Allah), whether he be of those who have committed great sins or small sins (kaba'ir, sagha'ir)2. As for those persons who have repented of their evil deeds, they are not in need of intercession. Says the Prophet: May Allah not grant my intercession to him who does not believe in my (power of) intercession. And he (the Prophet) said: No mediator (shafi') is more successful than repentance (tawba)3.
(The right of) intercession belongs to prophets (anbiya') and awsiya'4. And among believers (mu'minln) also there are some who can intercede on behalf of people equal in number to the tribes of Rabi'a and Mudar.5 Even the least of believers will be liable to intercede on behalf of 30,000.6
There can be no forgiveness for skeptics (ahlu'sh-shakk) and polytheists (ahlu'sh-shirk); nor for unbelievers (ahlu'l-kufr) and those who are persistent in their denial (ahlu'l-juhud). But the sinful amongst those who believe in the unity of Allah (ahlu't-tawhid7) may be forgiven.