In order that God may separate the wicked from the good…He [Sahl] said:Wickedness (khabīth) takes different forms: it may be disbelief (kufr), hypocrisy (nifāq), or grave sins (kabāʾir). Likewise goodness (ṭayyib) is manifested in different forms: [that is to say], goodness is faith (īmān), within which are included the [different] ranks of the prophets (anbiyāʾ), veracious (ṣiddīqūn), martyrs (shuhadāʾ) and virtuous (ṣāliḥūn). God, Exalted is He, has informed us that He has separated them from one another [i.e. the good from the bad], and He then ranks the corrupt, one above the other, according to the measure of each of their sins, level upon level, just as He has said: Verily the hypocrites will be in the lowest level of the Fire [4:145].His words: