What does Chapter 4 reveal about the selfless nature and ultimate purpose of a saint's mission on Earth?

Chapter 4 explains that saints are naturally liberated beings who incarnate on Earth purely for the benefit of others, with no self-interest. Their mission is to uplift the distressed, protect the humble and weak, and destroy irreligion. The chapter states that they come to awaken religion when people have lost their way, focusing only on worldly happiness and forgetting the ultimate goal. As detailed in Chapter 4, they build a 'temple of Ultimate Truth' on a 'foundation of Renunciation' and work to awaken faith among devotees. Once their specific work is fulfilled, they end their incarnation, having completed their selfless mission.