Formalism looks to treat each work as an individual piece, apart from the time period, author, etc. Formalists also assume that understanding a text comes from the text itself through form especially.
The Poisonwood Bible is undeniably a formalistic novel. It is about a white family traveling to the Congo during a time period where such was unthinkable. By going to a place where they are the only whites, they are disregarding American cultural norms, as most would think such a feat unthinkable. They bring various items with them from home, only to find that such items are useless in such a varying location. The Congo stands on its own as a part and America as another. The Poisonwood Bible largely focuses on the attempted merging of these two parts, with little success.
Furthermore, the format of The Poisonwood Bible reflects formalism. The sectioning of this novel into chapters narrated by different individuals creates sections that stand alone. Each female brings a specific perspective that sets her chapter apart. Yet, put together, the chapters form the complete story.