Religion is important in Comala. Every character is Catholic, so each has an understanding of the idea of God’s grace. To be welcomed into heaven after death, a character must be without sin—a state obtained through penitence and absolution. As such, the characters’ actions are largely dictated by their proximity to, or distance from, God’s grace. As the narrative unfolds, however, it becomes increasingly apparent that morality becomes easily corrupted when sin and hypocrisy are left to run unchecked.

Some characters attempt to be moral, or to at least accept responsibility for their actions and try to atone. Dona Eduviges, for example, is a fervent believer. She visits confession and admits to minor sins and infractions, hoping that she can return to God’s grace. She is kind and moral, but her death by suicide is regarded as an unforgivable offense by the church authorities. She wanders through Comala as a lost spirit, forever removed from God’s grace but hoping that someone’s prayers may one day help her to achieve absolution. Even after death, even after being permanently excluded from heaven, the ghostly Eduviges is guided by her proximity to God’s grace. Her interactions with Juan, for example, are guided by her hope that he will pray for her.