How does the text describe the process for achieving supreme devotion through a state of oneness?

According to the teachings in Chapter 4, the path to supreme devotion begins with the spiritual practice of discarding the feeling of duality. One must come to the realization that everything in the universe, both moving and unmoving, is inherently Brahman. The text explains that when a person fully realizes "I am everything" in relation to the entire world, they attain a state of happiness so profound that it leads to supreme devotion. This state of 'I-ness' removes the basis for enmity or fear, as nothing is perceived as separate from the self.