Such an allusion to the Romans, in an exposition like the present one, is not without its significance. It was partly through political circumstances that a truly theistic idea was developed out of the chaotic and fragmentary ghost theories and nature-worship of the primeval world. To the framing of the vastest of all possible conceptions, the idea of God, man came but slowly. This nature-worship and ancestor-worship of early times was scarcely theism. In their recognition of man's utter dependence upon something outside of himself which yet was not wholly unlike himself, these primitive religions contained the essential germ out of which theism was to grow; but it is a long way from the propitiation of ghosts and the adoration of the rising sun to the worship of the infinite and eternal God, the maker of heaven and earth, in whom we live, and move, and have our being. Before men could arrive at such a conception, it was necessary for them to obtain some integral idea of the heaven and the earth; it was necessary for them to frame, however inadequately, the conception of a physical universe. Such a conception had been reached by civilized peoples before the Christian era, and by the Greeks a remarkable beginning had been made in the generalization and interpretation of physical phenomena. The intellectual atmosphere of Alexandria, for two centuries before and three centuries after the time of Christ, was more modern than anything that followed down to the days of Bacon and Descartes; and all the leaders of Greek thought since Anaxagoras had been virtually or avowedly monotheists. As the phenomena of nature were generalized, the deities or superhuman beings regarded as their sources were likewise generalized, until the conception of nature as a whole gave rise to the conception of a single Deity as the author and ruler of nature; and in accordance with the order of its genesis, this notion of Deity was still the notion of a Being possessed of psychical attributes, and in some way like unto Man.

But there was another cause, besides scientific generalization, which led men's minds toward monotheism. The conception of tutelar deities, which was the most prominent practical feature of ancestor-worship, was directly affected by the political development of the peoples of antiquity. As tribes were consolidated into nations, the tutelar gods of the tribes became generalized, or the god of some leading tribe came to supersede his fellows, until the result was a single national deity, at first regarded as the greatest among gods, afterwards as the only God. The most striking instance of this method of development is afforded by the Hebrew conception of Jehovah. The most primitive form of Hebrew religion discernible in the Old Testament is a fetichism, or very crude polytheism, in which ancestor-worship becomes more prominent than nature-worship. At first the teraphim, or tutelar household deities, play an important part, but nature-gods, such as Baal, and Moloch, and Astarte, are extensively worshipped. It is the plural elohim who create the earth, and whose sons visit the daughters of antediluvian men. The tutelar deity, Jehovah, is originally thought of as one of the elohim, then as chief among elohim, and Lord of the hosts of heaven. Through his favour his chosen prophet overcomes the prophets of Baal, he is greater than the deities of neighbouring peoples, he is the only true god, and thus finally he is thought of as the only God, and his name becomes the symbol of monotheism. The Jews have always been one of the most highly-gifted races in the world. In antiquity they developed an intense sentiment of nationality, and for earnestness and depth of ethical feeling they surpassed all other peoples. The conception of Jehovah set forth in the writings of the prophets was the loftiest conception of deity anywhere attained before the time of Christ; in ethical value it immeasurably surpassed anything to be found in the pantheon of the Greeks and Romans. It was natural that such a conception of deity should be adopted throughout the Roman world. At the beginning of the Christian era the classic polytheism had well-nigh lost its hold upon men's minds; its value had become chiefly literary, as a mere collection of pretty stories; it had begun its descent into the humble realm of folk-lore. For want of anything better people had recourse to elaborate Eastern ceremonials, or contented themselves with the time-honoured domestic worship of the lares and penates. Yet their minds were ripe for some kind of monotheism, and in order that the Jewish conception should come to be generally adopted, it was only necessary that it should be freed from its limitations of nationality, and that Jehovah should be set forth as Sustainer of the universe and Father of all mankind. This was done by Jesus and Paul. The theory of divine action implied throughout the gospels and the epistles was the first complete monotheism attained by mankind, or at least by that portion of it from which our modern civilization has descended. Here for the first time we have the idea of God dissociated from the limiting circumstances with which it had been entangled in all the ethnic religions of antiquity. Individual thinkers here and there had already, doubtless, reached an equally true conception, as was shown by Kleanthes in his sublime hymn to Zeus;[9] but it was now for the first time set forth in such wise as to win assent from the common folk as well as the philosophers, and to make its way into the hearts of all men. Its acceptance was hastened, and its hold upon mankind immeasurably strengthened, by the divinely beautiful ethical teaching in which Jesus couched it,—that teaching, so often misunderstood yet so profoundly true, which heralded the time when Man shall have thrown off the burden of his bestial inheritance and strife and sorrow shall cease from the earth.[10]

We shall presently see that in its fundamental features the theism of Jesus and Paul was so true that it must endure as long as man endures. Changes of statement may alter the outward appearance of it, but the kernel of truth will remain the same forever. But the shifting body of religious doctrine known as Christianity has at various times contained much that is unknown to this pure theism, and much that has shown itself to be ephemeral in its hold upon men. The change from polytheism to monotheism could not be thoroughly accomplished all at once. As Christianity spread over the Roman world it became encrusted with pagan notions and observances, and a similar process went on during the conversion of the Teutonic barbarians. Yuletide and Easter and other church holidays were directly adopted from the old nature-worship; the adoration of tutelar household deities survived in the homage paid to patron saints; and the worship of the Berecynthian Mother was continued in that of the Virgin Mary.[11] Even the name God, applied to the Deity throughout Teutonic Christendom, seems to be neither more nor less than Wodan, the personification of the storm-wind, the supreme divinity of our pagan forefathers.[B]

That Christianity should thus have retained names and symbols and rites belonging to heathen antiquity was inevitable. The system of Christian theism was the work of some of the loftiest minds that have ever appeared upon the earth; but it was adopted by millions of men and women, of all degrees of knowledge and ignorance, of keenness and dullness, of spirituality and grossness, and these brought to it their various inherited notions and habits of thought. In all its ages, therefore, Christian theism has meant one thing to one person, and another thing to another. While the highest Christian minds have always been monotheistic, the multitude have outgrown polytheism but slowly; and even the monotheism of the highest minds has been coloured by notions ultimately derived from the primeval ghost-world which have interfered with its purity, and have seriously hampered men in their search after truth.

In illustration of this point we have now to notice two strongly contrasted views of the divine nature which have been held by Christian theists, and to observe their bearings upon the scientific thought of modern times.