Yama, god of the dead, identical with Yima, ruler of paradise, and especially Mitra, the cult of whose Persian counterpart, Mithra, obtained from 200-400 A.D. a world-wide diffusion in the Roman Empire, and came nearer to monotheism than the cult of any other god in paganism.
Various religious practices can also be traced back to that early age, such as the worship of fire and the cult of the plant Soma (the Avestan Haoma). The veneration of the cow, too, dates from that time. A religious hymn poetry must have existed even then, for stanzas of four eleven-syllable (the Vedic trishṭubh) and of four or three eight-syllable lines (anushṭubh and gāyatrī) were already known, as is proved by the agreement of the Avesta with the Rigveda.
From the still earlier Indo-European period had come down the general conception of "god" (deva-s, Lat. deu-s) and that of heaven as a divine father (Dyauṣ pitā, Gr. Zeus patēr, Lat. Jūpiter). Probably from an even remoter antiquity is derived the notion of heaven and earth as primeval and universal parents, as well as many magical beliefs.
The universe appeared to the poets of the Rigveda to be divided into the three domains of earth, air, and heaven, a division perhaps also known to the early Greeks. This is the favourite triad of the Rigveda, constantly mentioned expressly or by implication. The solar phenomena are referred to heaven, while those of lightning, rain, and wind belong to the air. In the three worlds the various gods perform their actions, though they are supposed to dwell only in the third, the home of light. The air is often called a sea, as the abode of the celestial waters, while the great rainless clouds are conceived sometimes as rocks or mountains, sometimes as the castles of demons who war against the gods. The
