Contrasts can provide powerful and memorable support for an argument. ON page 332, lines 446-448, identify at least one contrast between what King expected from religious leaders and what actually happened.

From the text:

I have heard numerous southern religious leaders admonish their worshipers to comply with a desegregation decision because it is the law, but I have longed to hear white ministers declare: "Follow this decree because integration is morally right and because the Negro is your brother."