As Calpurnia brings Scout and Jem to her church she is met with stares from all the black members and her path is blocked from Lula. Lula wants to know why Calpurnia is "bringin' these white chilluns' to a black church?" The purpose of this interaction is to demonstrate how uncomfortable situations can become when people cross out of their comfort zone. By going to the black church Scout and Jem see what it is like to be a minority. They also learn about tolerance and acceptance through the actions of the other members. "Each of Harper Lee’s characters, whether major or minor, provides a view of human nature and plays an integral part in the development of the plot and the pervading themes of To Kill a Mockingbird."
"The children find themselves in conflict with others. They are in a different segment of society. They, not Calpurnia or Tom Robinson, are the outsiders this time. They feel the sting of being “out of their place in society.” Jem asks to go home because “they don’t want us here.” Scout agrees. “I sensed, rather than saw, that we were being advanced upon.”
This scene illustrates a couple of different things:
1. It shows that people of any color, class, or description can become uncomfortable with dramatic change or alteration of the usual. Lula serves as an example of this fear when she interrogates Calpurnia about her intent in bringing the Finch children to the service.
2. It also shows the value and merit of Calpurnia as a loyal ally of the Finches. She doesn't back down, she doesn't apologize, she just goes on about the business of church with the children in tow, illustrating her own dignity and quiet confidence. The kids learn that despite differences in methodology, the church service isn't that different from their average Sunday at their own church.