Deities in Rig Veda are numerous. In these hymns one can see mythology in the making. Many of the hymns are not addressed to a sun-god, nor to a moon-god, nor to a fire-god, nor to a god of the heavens, nor to storm-gods and water-deities, nor to a goddess of the dawn and an earth-goddess, but the shining sun itself, the gleaming moon in the nocturnal sky, the fire blazing on the hearth or on the altar or even the lightning shooting forth from the cloud, the bright sky of day, or the starry sky of night, the roaring storms, the flowing waters of clouds and of rivers, the glowing dawn and the spread-out fruitful earth. All these natural phenomena are, as such, glorified, worshipped, and invoked.

Gradually, these natural phenomena were transformed into mythological figures and Gods. Thus we see the emergence of Gods such as Lord Surya (Sun), Soma (Moon), Lord Agni (Fire), Dyaus (Sky), Maruts (Storms), Vayu (Wind), Apas (Waters), Ushas (Dawn), and Prthivi (Earth), whose names still indubitably indicate what they originally were. So the songs of the Rig Veda prove indisputably that the most prominent inures of mythology have proceeded from personifications of the most striking natural phenomena.

Mythological investigation has succeeded, also in the cases of the deities whose names are no longer so transparent, in proving that they originally were nothing but just natural phenomena similar to sun, moon, and so on. Among such mythological figures, whose original nature is soon partly forgotten in the hymns, and who are honoured more as mighty, lofty beings, distinguished through all kinds of miraculous deeds, are Indra, Lord Varuna, Mitra, Aditi, Lord Vishnu, Pusan, the two Asvins, Rudra and Parjanya. These gods` names, too, originally indicated natural phenomena, and natural beings. Epithets, which at first emphasized a particularly important side of a natural being, became gods` names and new gods. Thus Savitar, the "inspirer," "the life-giver," and Vivasvat, "the shining," were at first epithets, then names of the sun, and finally they became independent sun-gods beside Surya.

Also the gods of different tribes and different periods are in many ways represented in the polytheism of the Vedic Indians. Hence it is that Mitra, Vishnu and Pushan also appear in the Rig Veda as sun-gods. Pushan was probably the sun-god of a small shepherd-tribe, before he was received into the Vedic pantheon as the "Lord of the ways," the protector of travellers, the god who knows all the paths and also brings back to the right path the cattle which have strayed. Mitra, who is identical with the Mithra of the Avesta, is through this fact already distinguishable as an ancient Aryan sun-god, who still hails from the time when Indians and Iranians formed one people.

It is not so easy with all gods to discover to which natural phenomenon they owe their origin. Still the opinions of investigators differ widely in the explanation of gods like Indra, Varuna,Rudra, Aditi and the Asvins-to mention only the most important ones. Thus, to one, Indra is the god of the storm, to the other an old sun-god. Varuna is to some a god of the heavens, while others see in him a moon-god. Rudra, who is usually held to be a storm-god, because he is the father of the storm-gods (the Maruts), would be a mountain and forest god according to some, a god of the horrors of the tropical climate to others. Aditi is, according to one view, the expanse of the sky, according to another the endless, wide spreading earth. The two Asvins, a pair of gods are a puzzle to the ancient Indian commentators. Some held them to be heaven and earth, others day and night, and still today some scholars see in them the two twilights, others sun and moon, yet others the morning and evening star, and again others the constellation of Gemini.

However, whatever be the difference of opinion regarding the actual Gods, it is seen for a fact that by far the greatest majority of the Vedic gods has proceeded from natural phenomena or natural beings. There were, indeed, some deities that have become divine beings out of abstractions, but they nearly all appear only in the latest hymns of the tenth book. In this category can be mentioned the names of a few deities as follows- Visvakarman- the world master-builder, Prajapati- the lord of creatures, Sraddha- faith, Manyu- anger, and some similar personifications.

There are also a number of Gods of lower mythology who appear in the Rig Veda. Numerous demons and evil spirits too appear in the hymns as enemies of the gods, who are hated and fought against by the Devas or gods. The name Asura, however, by which in the later Vedic works these enemies of the gods are designated, appears in the Rig Veda still with the old meaning "possessed of wonderful power" or "god," which the corresponding word Ahura has in the Avesta, and only in a few places also with the meaning of demons. In the Rig Veda Dasa or Dasyu is the usual name for the evil demons, besides also Raksas or Raksasas, by which, in the Rig Veda, as well as in the whole of the later Indian literature, all kinds of mischievous, ghostly beings are designated.

The Pitaras, i.e., the fathers or ancestral spirits, also received divine worship. The king of these ancestral spirits, who rules in the kingdom of the deceased, high up in the highest heaven, is Lord Yama, a god who belongs already to the Indo-Iranian prehistoric period, for he is identical with Yima who, in the Avesta, is the first human being, the primeval ancestor of the human race. As the first departed one, perhaps originally the daily setting sun or the monthly dying moon, he became the king in the realm of the dead. This kingdom of the dead is in the heavens, and the dying man is comforted by the belief that after death he will abide with King Yama in the highest heaven. No trace is found in the Rig Veda of the transmigration of the soul and eternal rebirth. So there is seen here in these hymns there breathes an entirely different spirit from that which pervades the whole of the later Indian literature.