The text mentions a 'State of Oneness.' Can you explain this philosophical concept as it is described in the source?

The philosophical concept of the "State of Oneness" is a central theme discussed in Chapter 4. It is described as a state achieved by discarding the feeling of duality, where one perceives that everything in existence—both moving and unmoving—is inherently Brahman. This realization leads to the profound understanding that "the glory of the universe is our own, the eternal majesty of Brahman." The text posits that when an individual truly realizes "I am everything" in relation to the entire world, they attain supreme devotion and a happiness beyond description. In this state of non-duality, there is no basis for enmity or fear, as nothing is perceived as separate from the Self.