Part of the religion theme is the difference in types of faith.  The priest is upset when they do not come to him to perform a proper funeral mass.  It is interesting that they don't have total faith in Catholicism, but yet they trust a priest to have the power to make holy water.  What makes a priest able to make holy water, yet unable to send rainclouds?  What makes their faith in their grandfater to bring rainclouds valid, if he cannot do so without the help of a priest?  It's like Hannah says... a delicate balance of cultures... the Native American culture, and the Catholic culture into which they're being assimilated.