Why did kino and juana have to leave la paz?

Kino and Juana had to leave La Paz primarily to escape the danger and persecution following the theft of Kino's valuable pearl. The greed and violence it incited attracted hostile attention from those who sought to take the pearl for themselves, putting Kino, Juana, and their child in jeopardy. Additionally, their decision to leave reflects their desire to protect their family and seek a better life away from the corruption and exploitation they faced in the town.