And those that relate what they have in common with those who went before, what evil actions are characteristic of them, and where their souls will end up in the afterlife.
This certainly seems to be referencing the belief that those who do not share one’s religion are doomed. Many people believe, as it does say this in a lot of scripture throughout various religions, that people who sin or do not follow said religion will go to hell, or will end up in a bad place during their afterlife. This is one of the things that makes religion so powerful; people become fearful of what may occur in the afterlife if they neglect God and their purpose for him. Whether or not God is real, fear of the afterlife is definitely a reason that people are driven to believe in and follow the indoctrinations of religion. Al Farabi absolutely needed to include this as a crucial element of religion.