What is identified as the ultimate root of our worldly illusion, and what is the sole method for its removal?

The text in Chapter 50 identifies the root cause of all worldly illusion as Avidya, which is synonymous with ignorance, Maya, and Avidya-Prakriti-Pradhan. This ignorance is the cause of the causal body and the entire delusive experience of the world, where one thing appears as something else, like a rope appearing as a snake. The scripture is unequivocal that there is only one way to overcome this fundamental problem. The removal of ignorance is possible only through the attainment of the knowledge of the unity of Brahman and the Soul. When this unifying knowledge occurs, ignorance is dispelled, and true knowledge arises, leading to liberation.