Religion plays an integral role in Marci’s story. Her primary goals are both expressed as prayers to Catholic figures: Jesus, the Virgin Mary, and God. From the beginning, however, Marci finds it difficult to navigate the relationship between religion and science. The questions she asks Sister ‘Lizabeth are rooted in that conflict. She is bothered by the fact that the Bible does not give any information about dinosaurs, for example, and she is often told that having faith in God is more important than her curiosity.

The theme does not strictly appear in terms of religion, however. Delia has complete faith in Eddie; she allows him to dictate her actions, and Marci repeatedly mentions that Delia does not have any thoughts of her own. Eddie is in complete control. Marci prays to the Virgin Mary to put knowledge in Delia’s head so that she will leave Eddie. Delia’s inability to question her faith results in inaction, which hurts her and her daughters.

In addition, Leti puts faith in her folk remedies. Her belief in their power is so strong that she gives the girls powder that is meant to change Eddie’s behaviors, but she does not help them leave their dangerous situation.