What is the ultimate purpose of a saint's incarnation as explained in Chapter 4, and is there any self-interest involved?

The teachings in Chapter 4 of Sai Satcharitra state unequivocally that the incarnation of saints is entirely for the benefit of others, with no personal motive. The text makes this clear by stating, "Their incarnation is purely for the sake of others; they have no self-interest." Saints are described as being naturally liberated souls who descend to this mortal world to perform a specific mission. This mission involves protecting the humble and poor, destroying irreligion, and re-establishing the system of castes and stages of life. They come to awaken religion when people have lost their way, guiding devotees toward the ultimate spiritual goal.