What are the themes and symbols in the story? What role do the symbols play in the story, and how do the symbols connect to the theme?

The theme of the story is the intersection of Christianity with Laguna beliefs in pueblo culture and how they come into play with regard to mortality.
The symbols in the story mostly have to do with each respective culture's religious and spiritual rituals. The corn meal and pollen are sprinkled onto Teofilo by Leon as a purification rite. His face is painted, and his body is carefully prepared for the next life in new clothing. New rope is used to secure the blanket to his body and lower him into his grave. Leon is satisfied with the ritual until Louise asks for the Catholic priest's blessing in the form of holy water.
Father Paul of the local Catholic church is at first reluctant to sprinkle Teofilo's body with the symbolic holy water because some of the required Catholic rituals have not been observed. Ultimately, however, the holy water is applied at Teofilo's gravesite by the priest. Leon feels that the holy water will encourage the gods to send much needed rain, while the priest's belief is that the water is a reminder of baptism.
The story encapsulates the uneasy relationship between Catholic and Native spiritual traditions and how they coexist and, in some ways, overlap.
https://www.indianpueblo.org/brief-history-pueblo-catholicism/