What is the primary cause for a soul being trapped in the perpetual cycle of birth and death, also known as Samsara?

According to the teachings in Chapter 37, the primary reason a soul remains subject to the eternal cycle of worldly existence (Samsara) is the perception of duality and difference. A person who holds the belief, "Parabrahman is different from me; I am not that, I am something else," is deluded by ignorance. This sense of being separate from the ultimate reality, Brahman, ensures that death follows birth and rebirth follows death, trapping the individual in this unending cycle.