All these testify that early man believed in a power or powers outside himself, and that his chief passion was to know and do the will of his god or gods. Jesus himself bore witness in the opening words of the prayer which he taught his disciples, that this is the essence of religion. It was natural and inevitable that primitive man, with his naive view of the universe, should believe not in one but in many forces or spirits, and that he should first enthrone the physical above the ethical and spiritual. It is the instinctive tendency of the child to-day. The later identification of the divine powers with the sun, that gave light and fertility to the soil, or with the moon, that guided the caravans by night over the arid deserts, or with the other heavenly bodies, that moved in majestic array across the midnight sky, was likewise a natural step in the evolution of primitive belief. [Sidenote: _Reasons why Babylonia developed an early civilization_] Civilization and religion in antiquity developed, as a rule, side by side. The two great rivers, the Tigris and the Euphrates, commanding the trade of the north and the south; proximity to the desert with its caravans of traders going back and forth from the Euphrates to the Nile; the rich alluvial soil, which supported a dense population when properly drained and cultivated; and the necessity of developing in a higher degree the arts of defence in order to maintain the much contested territory,--these were a few of the many conditions that made ancient Babylonia one of the two earliest if not the oldest centre of human civilization. The commercial habits and the abundance of the plastic clay, which could easily be moulded into tablets for the use of the scribe, also fostered the early development of the literary art. The durability of the clay tablets and the enveloping and protecting qualities of the ruined mounds of ancient Babylonia have preserved in a marvellous way its early literature. The result is that we can now study, on the basis of contemporary documents, this early and yet advanced chapter in that divine revelation, the later culmination of which is recorded in the Bible. [Sidenote: _Progress during the period of city states_]