Monotheism, belief in the existence of one god, or in the oneness of God. As such, it is distinguished from polytheism, the belief in the existence of many gods, from atheism, the belief that there is no god. Monotheism characterizes the traditions of Judaism, Christianity, and Islam, and elements of the belief are discernible in numerous other religions.
The choice of either monotheism or polytheism, however, leads to problems, because neither can give a satisfactory answer to all questions that may reasonably be put. The weakness of polytheism is especially revealed in the realm of questions about the ultimate origin of things, whereas monotheism runs into difficulties in trying to answer the question concerning the origin of evil in a universe under the government of one god.
Exclusive monotheism
For exclusive monotheism only one god exists; other gods either simply do not exist at all or, at most, are false gods or demons— This position is in the main that of Judaism, Christianity, and Islam. While in the Hebrew Bible (Old Testament) the other gods in most cases were still characterized as false gods, in later Judaism and in Christianity as it developed theologically and philosophically, the conception emerged of God as the one and only, and other gods were considered not to exist at all.
For monotheism there are two basically different realities: God and the universe. God in monotheism is conceived of as the creator of the world and of humanity. God has created not only the natural world and the order existing therein but also the ethical order to which humanity ought to conform and, implicit in the ethical order, the social order. Everything is in the hands of God. Human beings approached with attitudes of both repulsion and attraction, of both fear and love. The God of monotheism, as exemplified by the great monotheistic religions—Judaism, Christianity, and Islam—is a personal god.
The basic monotheistic view
The God of monotheism is the one real god that is believed to exist or, in any case, that is acknowledged as such. God’s essence and character are believed to be unique and fundamentally different from all other beings that can be considered more or less comparable—e.g., the gods of other religions.
Inclusive monotheism
Inclusive monotheism accepts the existence of a great number of gods but holds that all gods are essentially one and the same, so that it makes little or no difference under which name or according to which rite a god or goddess is invoked.
Religious dualism
Some religions are in the main dualistic: they view the universe as comprising two basic and usually opposed principles, such as good and evil or spirit and matter. The most important instance of dualism within a religion is the Iranian religion Zoroastrianism, which emerged out of the teachings of the prophet and priest Zarathustra, in which Ahura Mazdā (the “Wise Lord,” or the good, supreme god) and Ahriman (Angra Manyu, the destructive spirit) are each other’s opposite and implacable enemy; at the end of time, Ahura Mazdā will defeat Ahriman. Dualism, the existence of two contrary and, as a rule, mutually inimical principles, must not be confused with the notion of polarity, in which both principles are mutually dependent so that the one cannot exist without the other.
Pluriform monotheism
The complicated relations that exist between monotheism and polytheism become clear when one considers pluriform monotheism, in which the various gods of the pantheon, without losing their independence, are at the same time considered to be manifestations of one and the same divine substance. Pluriform monotheism is one of the efforts to solve the problem of the coexistence of divine unity and divine pluriformity (multiplicity of forms), which was not recognized by an older generation of scholars, although part of the material was already available. It seems, indeed, that in many parts of the world and in many times religious thinkers have struggled with the perplexing problem of the unity and the pluriformity of the divine.
The Nuer, a Nilotic pastoral people of eastern South Sudan, venerate a being called Kwoth, the Nuer term for “spirit” (also translated as “God”). He is considered to be the spirit in or of the sky. Like all spirits, Kwoth is invisible and omnipresent, but he manifests himself in a number of forms. Each of these manifestations bears a name of its own, but though they are addressed and treated as separate entities, they are essentially nothing but manifestations of the one spiritual being Kwoth and are themselves considered spirits and called kwoth. A sacrifice offered to one of these manifestations—e.g., a spirit of air, totem, or place—is not at the same time an offering to another, but all sacrifices, to whatever spirit they are offered, are sacrifices to the supreme Kwoth, or God. Nuer religion is certainly no clear monotheism as it is understood in the Bible and in the Quran (the sacred book of Islam), but neither is it polytheism in the popular sense of the word.
Henotheism, or kathenotheism
Henotheism —the worship of one god, though the existence of other gods is granted—also called kathenotheism —which literally implies worship of various gods one at a time—has gone out of fashion as a term. It was introduced by the eminent 19th-century philologist and scholar in comparative mythology and religion Max Müller. Many later authors preferred the term monolatry—which is the worship of one god, whether or not the existence of other deities is posited—to the term henotheism. Both terms mean that one god has a central and dominating position in such a way that it is possible to address this god as the one and only god without, however, abandoning the principle of polytheism by denying or in any other way belittling the real existence of the other gods, as the above-mentioned forms of monotheism do. Henotheism as a religious concept is at home in cultures with a highly centralized monarchical government. It was especially prevalent in some periods in the history of Babylonia and Egypt.
Unlimited polytheism
On the other hand, there is the extreme position of unlimited polytheism, as, for instance, in the classical religions of Greece and Rome: the various gods have their own names and their own shapes, and these are inalienably their own and cannot be exchanged with those of any other god . The number of divinities is large and in principle unlimited. There are differences of status and power between the gods, of function and sphere of influence, but they are all equally divine. There is, in fact, an ordered pantheon. In unlimited polytheism, the number of gods that are actually worshipped seldom exceeds a few hundred within one religion, but in theory, as in India, millions and millions of gods may be thought to exist.