Why don't the Guarani's trust the Jesuit missionaries at the beginning of the film The MIssion?

At the beginning of the film "The Mission," the Guarani people are wary of the Jesuit missionaries because they have a history of exploitation and oppression from European colonizers. The missionaries represent a foreign authority that threatens their way of life and autonomy. Additionally, the Guarani's initial mistrust is compounded by their experiences with betrayal, leading them to be cautious about the missionaries' true intentions. This skepticism reflects their desire to protect their culture and sovereignty.