Can you explain the purpose of a saint's incarnation as detailed in Chapter 4, particularly in relation to worldly activity (Pravritti) and renunciation (Nivritti)?

As detailed in Chapter 4, the purpose of a saint's incarnation is to restore religion and guide humanity. The chapter presents a sophisticated model for how they achieve this by stating that saints "fill the foundation of Renunciation (Nivritti) and build the temple of Ultimate Truth." This means their work is grounded in detachment and spiritual wisdom. Upon this foundation, they operate within the "frame of Worldly Activity (Pravritti)," using their engagement with the mortal world to easily uplift devotees. Their mission is to perform the work of religion and awaken faith. This selfless work is done entirely for the sake of others, as saints themselves are already liberated and have no personal agenda.