These Avatars and sons of God do not limit their message of returning to God to human society alone; their activity also extends to all other categories of beings, from virtuous saints and celestial beings to beings lower than humankind.

The ultimate goal of existence is to seek to know Krishna, God, the Supreme Personality, as He truly is.

The ultimate goal of existence is also to return to Krishna, to His infinite, absolute, and eternal kingdom, in order to regain the position of eternal servant that we had with Him at the beginning of all things.

What is the evolutionary cycle of species?

Evolutionary cycle of species, or the soul's journey through species.

Lord Krishna teaches us about the hierarchy of beings and the different species.

Among the creations produced by the two manifested energies [spirit and inert matter], those possessing life force [vegetables, grass, trees, and plants in general] dominate over inert matter, stone, earth, etc.

In turn, reptiles, worms, and snakes, which are capable of movement, surpass immobile plants, and animals with developed intelligence are superior to even reptiles.

Human beings are superior to animals, and ghosts to human beings, because they do not have physical bodies.

Above the ghosts are the Gandharvas (celestial singers) and, even higher, the Siddhas (perfect beings), then the Kinnaras (superhuman beings with supernatural powers), and finally the asuras (unenlightened, evil beings, who can subdue the aforementioned beings).

Above the asuras come the celestial beings, ruled by Indra, the king of the heavens. The direct sons of Brahma, including King Daksa, prevail over Indra, and of Brahma's sons, Siva is the greatest. Since Siva is the son of Brahma, the latter is considered superior to him, but Brahma himself is subordinate to Me, the Supreme Lord.

However, since I Myself am favorable to learned sages, they are the greatest of all.

The different levels of spiritual elevation, from the smallest to the highest devotee.

Animate beings are superior to inanimate objects, and among them, those in which the signs of life are manifested are more evolved. As for animals endowed with developed consciousness, they are superior to them, and above them are beings endowed with developed sensory perception.

Among beings endowed with sensory perception, those with developed taste are superior to those with developed touch. But superior to them are those who can smell, and even superior to those who can hear.