The book "The Poisonwood Bible" is the story of a baptist minister who takes his family and moves to the Belgian Congo. The minister is the girl's first vision as God. However, he makes some very poor choices that have terrible consequences for the family. The father's decisions lead to his daughter's frustration with him and dismay. He eventually loses his mind.
The use of the Bible Text titles serves as a reminder that the father's decisions were the Bible for the family. They had no choices and were faithful to their father and wanting to please him. Genesis represents the beginning when the earth was made but in the book Nathan's wife is looking back having left the Congo years before.