The planets of a galaxy are divided into three planetary systems of different levels; are the lower planets called Hell, the intermediate planets of terrestrial types, and the Edenic, paradisiacal upper planets.
The earth and its inhabitants the human beings, is located at the beginning of the intermediate system, while Brahma, the demiurge, the first created being and regent of our galaxy appointed to this post by God, he and his peers live on the higher planets, the highest of which is Satyaloka also called Brahmaloka.
The inhabitants of the latter perfectly master spiritual wisdom, so that for them, the mystical cloud of material energy dissipates, they are therefore called by the name of “knowing personified”. Fully awakened to material and spiritual knowledge, they do not pursue any personal interest, whether in the material or spiritual worlds.
They can practically be called “holy wise men without desires”, because they have no nothing to pursue in the material universe, and they find in themselves their fullness in the spiritual world. Why then do they come here?
The answer is simple, they descend to different planets in our galaxy “the Milky Way”, at the behest of Lord Krishna, God the Supreme Person, to fulfill the role of Messiah there, and free the fallen souls, who reside there.
They appear on earth for example, in different places and in various circumstances, in various climates, and thus do the good of all human beings. But apart from their divine mission, which consists in withdrawing from the illusory influence of material energy the souls embodied and conditioned by matter who live there and thus languish in their material existence, they have nothing to do in this world. At the end of their divine mission, they return to where they came from.
God also sends down from his kingdom his pure devotees as Messiahs.
Krishna, God, the Supreme Person, Himself regularly descends on a planet of a given galaxy, or send his pure devotee and authentic representative called messenger, son of God, companion or intimate servant.
By his will, the Sovereign Lord, Krishna, descends on the material planets in innumerable forms of Avatars for specific reasons, after which He returns to his kingdom. Avatar means “The one who descends”.
Let us know that neither the Supreme Person, nor the pure beings that He Himself sends to earth for example, are ordinary beings like the common human beings. A true messenger of the Lord is worth as much as God Himself.
Periodically, an envoy of the Lord appears as a ray of light, in order to teach the world the ultimate goal of existence. Noble heads of families pray to God to entrust them with one of his envoys, so that a favorable influence may be exercised on human society.