He (the soul) who sits in the body is eternal, he cannot be killed. So you don't have to mourn anyone.

In truth, ignorance of the data relating to God as He really is, to the existential truth, and to the sublime knowledge revealed by the Supreme Lord, is the cause of human suffering, enslavement, astray and perdition. Distress is born of ignorance. It is through ignorance that people commit a considerable number of malicious acts and get bogged down in matter, in corporal imprisonment, and do not know how to stop it.

That is why beings enlightened by true spiritual knowledge, superior to material knowledge, and revealed by Krishna, God, the Supreme Person, automatically become good.

Lord Krishna, God, says: “Like the blazing fire which converts wood into ashes, the brazier of knowledge reduces to ashes all the consequences of material actions”.

The knowledge contained in true spiritual knowledge acts as a fire, through which we can eliminate, destroy or reduce to ashes all sinful, malicious actions committed. This is why human beings need to be educated.

Born ignorant, spiritual education is required, in order to dispel their ignorance. Born into the illusion of the bodily conception of existence, people behave like animals that have only four activities, eating, sleeping, mating and defending themselves. It is therefore necessary to impart spiritual education to them, so that they understand that they are not the material body, but in reality an eternal spiritual soul. So they will behave differently.

The material nature is at the origin of all material bodies.

Each of us is, in truth, an immortal spiritual soul, a tiny fragment of God, an integral part of his Divine Person. We are not the body of dense matter in which we have incarnated, and to which we make the mistake of identifying ourselves permanently.

Each one of us is a spiritual soul enclosed in an ethereal body, and himself captive of a material body. All living beings, humans, animals and plants are trilogies, that is, they are all composed of a soul, their true spiritual identity, an ethereal body and a body of dense matter.

It is the material energy of God, better known by its material aspect, which provides living beings with the material bodies in which they will reincarnate.

Because the soul is embodied in a body of dense matter, it is in fact conditioned by material nature, whose influence it is subject to. Whatever material energy known in its aspect of material nature dictates to the soul, the latter accomplishes it, for it is not the soul that acts, but its material body.