What does Chapter 4 reveal about the selfless nature and ultimate mission of saints when they take birth?

According to the teachings in Chapter 4 of the Sai Satcharitra, saints are described as being naturally liberated, yet they are always ready to uplift the distressed. The text makes it clear that their incarnation is purely for the sake of others and that they have no self-interest. Their mission is to restore spiritual order by performing the work of religion and awakening faith. This chapter poetically describes their work as filling the foundation of Renunciation (Nivritti) to build the temple of Ultimate Truth, while easily uplifting devotees within the framework of Worldly Activity (Pravritti). Once their specific work is fulfilled, they end their incarnation.