The doctor is a self absorbed man. He only cares about money, and not peoples health. He was not willing to help Coyotito because he was not wealthy. Although, once Coyotito received the pearl it all changed.
The priest is full of virtue and goodness. However, similar to the doctor he really only cares about wealth and his church.
The towns people were friends with Coyotito, Kino, and Juana. Although, once they received the pearl the towns people became highly jealous of Kino and his family.