What is the ultimate mission of a saint, and what happens when their work is done, based on the information in Chapter 4?

Based on the teachings in Chapter 4, the mission of a saint is to re-establish a spiritual foundation for humanity. The text beautifully illustrates this by stating they 'fill the foundation of Renunciation (Nivritti) and build the temple of Ultimate Truth.' They work to uplift devotees and reawaken faith by performing the work of religion within the framework of worldly activity. The chapter clarifies that their incarnation is tied to a specific purpose; once their unique work is fulfilled and their mission is complete, they conclude their incarnation and depart from the mortal world.