This energy when tampered with by a guru in a person swings into reverse mode of destruction of the psyche of the person, resulting in Self-realization. The merger of the human being with the Divinity occurs, as the energy ascends along the cerebrospinal system of the person, thereby elevating the mind to higher and higher platforms.
Why is destruction or involution necessary? It is necessary because the creation or evolution of the human being needs to be undone by the same cosmic energy so that the underlying substratum or the Divinity, which is enshrined within the Self of every human being, can be revealed. This is what is called Self-realization or salvation.
How this energy in its reverse mode propels a person towards Immortality is what is called yoga.