Chapter 24 is the chapter where Scout attends one of Aunt Alexandra's missionary teas. There are a few theme subjects addressed in this chapter, including Scout learning lessons in growing up as a lady, Miss Maudie having the courage to stand up for what she believes in, and of course, the following:
The main theme that is reinforced here is the idea of hypocrisy as presented by the people of Maycomb. Here is a group of white women, all church going Christians, meeting with the purpose of discussing (and ultimately supporting) Christian mission work overseas.
While they are able to talk about "living a Christian life" and taking care of those people in the "jungle over there" and supporting mission work and spreading the love of Jesus Christ - in the same breath they can belittle the African Americans living in their own town.
And through this two-faced-ness, they even have the audacity to identify hypocrisy in others.