What does Chapter 37 say is the root cause of being trapped in the cycle of birth and death, and what is the way out?

The root cause of being trapped in the cycle of worldly existence (Samsara) is the deluded belief in one's separateness from the divine. Chapter 37 explains that a person who thinks, "Parabrahman is different from me; I am not that, I am something else," is always subject to the cycle of death and rebirth. The way to break free from this cycle is to overcome what the chapter calls the "nooses of death": unrighteousness, ignorance, anger, and hatred. By crossing these obstacles, the soul can enter the "divine heavenly state," which is the realization of the Cosmic Self, understanding that the same divine principle pervades all of creation without difference.