If you are referring to the excerpt from the Leslie Marmon Silko's story "The Man to Send Rain Clouds", I believe the correct answer is: The holy water is important to both the priest and Leon, but it is important for different reasons.
Through the holy water, in this story are presented two ways of thinking and two different religions and beliefs. Even though holy water is important from both Leon and priest – it’s important from different reasons.
For the priest the holy water is necessary part of religious ceremonies and it represents the belief in one God, but for Leon, holy water is a symbolic offering for the rain the season of drought. Leon hopes that blessed with holy water, his grandfather will send them lots of rain.