How does one progress from singular devotion to the Guru to the state of 'undifferentiated worship' (Abheda-bhajan)?

Chapter 45 outlines a path from devotion to the Guru to the advanced state of 'undifferentiated worship' (Abheda-bhajan). It begins with the disciple practicing discrimination between the eternal (Brahman) and the transient (the world). By recognizing the Guru as the true Brahman and renouncing the transient, the disciple cultivates dispassion (Vairagya). This leads to seeing the Sadguru as a solid mass of Brahman-consciousness. From this profound realization, divinity begins to arise in all beings, which is the essence of 'undifferentiated worship' as described in the chapter.