The black community in Maycomb is quite idealized, especially in the scenes at the black church and in the “colored balcony” during the trial. Lee’s portrayal of the black community isn’t unrealistic or unbelievable; it is important to point out, however, that she emphasizes all of the good qualities of the community without ever pointing out any of the bad ones. The black community is shown to be loving, affectionate, welcoming, pious, honest, hardworking, close-knit, and forthright. Calpurnia and Tom, members of this community, possess remarkable dignity and moral courage. But the idealization of the black community serves an important purpose in the novel, heightening the contrast between victims and victimizers. The town’s black citizens are the novel’s victims, oppressed by white prejudice and forced to live in an environment where the mere word of a man like Bob Ewell can doom them to life in prison, or even execution, with no other evidence. By presenting the blacks of Maycomb as virtuous victims—good people made to suffer—Lee makes her moral condemnation of prejudice direct, emphatic, and explicit.
Here, St. Paul is saying that people guilty of certain sins will not be saved. It may help to know that in the context, he is writing to believing Christians (“them that are sanctified in Christ Jesus” — 1:2) to exhort them not to do these things. Since even the Corinthian believers will not be saved if they go to their judgment guilty of these particular crimes, then avoidance of them is necessary — even for true believers.  Now, “avoidance” is an act — a work. Since it is a work that conforms us to God’s will, then it is a “good work.” Where that leaves us is — good works are necessary for salvation.