According to Chapter 4 of Sai Satcharitra, what are the primary reasons for saints to incarnate on Earth?

Chapter 4 of the Sai Satcharitra explains that saints incarnate on Earth during times of significant societal and religious decay. This occurs when people become fixated on worldly happiness from wealth and family, turning away from the ultimate spiritual goal, or Paramartha. As detailed in this chapter, saints descend to awaken religion, destroy irreligion, and protect the system of castes and stages of life. Their main purpose is to protect the humble, poor, and weak, and to uplift the distressed. The text emphasizes that their incarnation is purely for the benefit of others, as they are already liberated and have no personal self-interest in their mission.