Lord Krishna has countless energies, the three major of which are the internal energy by which He manifested the spiritual world, the external energy or material energy by which He created the material universe, and the marginal energy of which we are the components. The material energy under its aspect of material nature, acting under the authority of God, is at the origin of all the material bodies, human, animal and vegetal, and the material senses that are related to it.
In the conditioned state, embodied beings belonging to marginal energy are a combination of material and spiritual energy. Marginal energy is originally under the control of spiritual energy, but under the influence of material energy, fallen incarnate souls wander into oblivion within the material world, since time immemorial.
Krishna is absolute knowledge, and the Supreme Teacher. It was He who, at the origin of all things, while the universe was not yet manifested, taught the Vedic knowledge, from the Vedas, the original scriptures to the first created being, the demiurge, Brahma, in his heart.
Man is, in truth, a trilogy. The human being is composed of three parts.
The first, that which characterizes it is none other than the spiritual soul, of which it is the real representation.
The second is none other than the ethereal body which envelops the soul, and which is composed of the mind, the intelligence and the false ego or material ego.
The third part, the body of dense matter in which the ethereal body is enclosed. The material body is actually a mass of inert material elements, it is a dead mass, lifeless by itself.
It is the soul that gives it life, and thus allows it to move. The soul is at the origin of the life of the body, which without it would remain a dead mass. Consciousness being the major energy of the soul, it is by spreading it throughout the body that the soul becomes omnipresent and controls the whole body. Consciousness is none other than the soul itself, and provides evidence of the presence of the soul in the body.
The soul is at the origin of the existence of the body of dense matter or material body.
Forgetting our relationship with God is the cause of our chaining to the cycle of death and successive births, also called reincarnations.
In truth, it is the forgetting of the relationship that unites us to God that is at the origin of the destruction of our body. As spiritual entities, we are all as eternal as the Supreme Lord Himself. But because we forgot our true identity, we were placed in the material nature and forced to reincarnate, passing from one body to another, sometimes of a different form and nature. When our body is destroyed, we also believe that we perish at the same time. It is the body of matter in which we reside as an incarnate soul, which is at the origin of forgetting God, of our true spiritual identity, and of existential and absolute truth. The change of body is death.