What is the primary cause that perpetuates the cycle of worldly existence (Samsara)?

According to the insights in Chapter 37, the cycle of worldly existence, or Samsara, where death follows birth and rebirth follows death, is perpetuated by a specific form of ignorance. The text identifies the root cause as holding a 'knowledge of difference'. This is the mistaken belief that "Parabrahman is different from me; I am not that, I am something else." It is this consciousness of separation from the ultimate reality that ensures the eternal turning of the wheel of Samsara, binding the individual to the continuous cycle of life and death.