According to Chapter 4 of Sai Satcharitra, for what reason do saints choose to incarnate on Earth?

Chapter 4 of the Sai Satcharitra explains that saints incarnate on Earth during times of significant social and religious decay. As detailed in the chapter, this occurs when people lose their way, when religious teachers are insulted, sectarian hatred grows, and individuals become obsessed with worldly happiness over spiritual goals. Saints descend to protect the humble and the weak, destroy irreligion, and reawaken faith. Their incarnation is described as being purely for the sake of others, as they themselves are already liberated and have no self-interest in the matter, coming only to uplift the distressed.