God is most often conceived of as the supernatural creator and overseer of the universe. Theologians have ascribed a variety of attributes to the many different conceptions of God. The most common among these include omniscience, omnipotence, omnipresence, omnibenevolence (perfect goodness), divine simplicity, and eternal and necessary existence. God has also been conceived as being incorporeal, a personal being, the source of all moral obligation, and the "greatest conceivable existent". These attributes were all supported to varying degrees by the early Jewish, Christian and Muslim theologian philosophers, including Maimonides, Augustine of Hippo, and Al-Ghazali, respectively. Many notable medieval philosophers developed arguments for the existence of God, attempting to wrestle with the apparent contradictions implied by many of these attributes.
See main article: God (word). The earliest written form of the Germanic word god comes from the 6th century Christian Codex Argenteus. The English word itself is derived from the Proto-Germanic * ǥuđan. Most linguists agree that the reconstructed Proto-Indo-European form was based on the root , which meant either "to call" or "to invoke".
The capitalized form God was first used in Wulfila's Gothic translation of the New Testament, to represent the Greek Theos. In the English language, the capitalization continues to represent a distinction between monotheistic "God" and "gods" in polytheism.  In spite of significant differences between religions such as Christianity, Islam, Hinduism, the Bahá'í Faith, and Judaism, the term "God" remains an English translation common to all. The name may signify any related or similar monotheistic deities, such as the early monotheism of Akhenaten and Zoroastrianism.
See main article: Names of God.
Conceptions of God can vary widely, but the word God in English—and its counterparts in other languages, such as Latinate Deus, Greek Θεός, Slavic Bog, Sanskrit Ishvara, or Arabic Allah—are normally used for any and all conceptions. The same holds for Hebrew El, but in Judaism, God is also given a proper name, the tetragrammaton (usually reconstructed as Yahweh or YHWH), believed to hark back to the religion's henotheistic origins. In the Bible, when the word "LORD" is in all capitals, it signifies that the word represents the tetragrammaton. God may also be given a proper name in monotheistic currents of Hinduism which emphasize the personal nature of God, with early references to his name as Krishna-Vasudeva in Bhagavata or later Vishnu and Hari, or recently Shakti.
It is difficult to draw a line between proper names and epitheta of God, such as the names and titles of Jesus in the New Testament, the names of God in the Qur'an, and the various lists of thousand names of God and List of titles and names of Krishna in Vaishnavism.
Throughout the Bible there are many names for God that portray his nature and character. Elohim means “strong one.” It is especially used of God’s sovereignty, creative work, mighty work for Israel and in relation to his sovereignty (  ; Jer. 32:27; Gen. 1:1; Isa. 45:18; Deut. 5:23; 8:15; Ps. 68:7). El Shaddai “God Almighty.” (Gen. 17:1; 28:3; 35:11; Ex. 6:31; Ps. 91:1, 2). El Elyon means “The Most High God” and stresses God’s strength, sovereignty, and supremacy (Gen. 14:19; Ps. 9:2; Dan. 7:18, 22, 25).
In Chinese civilization, since at least the Shang Dynasty (1766 BC), the indigenous omnipotent conception of God has been called Shangdi (上帝, literally "Above Sovereign") or referred as Heaven (天). Whereas, the generic conception of god(s) and spirits in Chinese, including the Protestant Christian God, is called shen (神). The Catholic God in Chinese is called Tianzhu (天主, literally "Heavenly Lord"), though earlier missionaries such as Matteo Ricci also favored the use of the indigenous Shangdi. 
See main article: Conceptions of God. Conceptions of God vary widely. Theologians and philosophers have studied countless conceptions of God since the dawn of civilization. The Abrahamic conceptions of God include the trinitarian view of Christians, the Kabbalistic definition of Jewish mysticism, and the Islamic concept of God. The dharmic religions differ in their view of the divine: views of God in Hinduism vary by region, sect, and caste, ranging from monotheistic to polytheistic to atheistic; the view of God in Buddhism is almost non-theist. In modern times, some more abstract concepts have been developed, such as process theology and open theism. Conceptions of God held by individual believers vary so widely that there is no clear consensus on the nature of God. The contemporaneous French philosopher Michel Henry has however proposed a phenomenological approach and definition of God as phenomenological essence of Life.
See main article: Existence of God. Many arguments for and against the existence of God have been proposed and rejected by philosophers, theologians, and other thinkers. In philosophical terminology, such arguments concern schools of thought on the epistemology of the ontology of God.
There are many philosophical issues concerning the existence of God. Some definitions of God are sometimes nonspecific, while other definitions can be self-contradictory. Arguments for the existence of God typically include metaphysical, empirical, inductive, and subjective types, while others revolve around holes in evolutionary theory and order and complexity in the world. Arguments against the existence of God typically include empirical, deductive, and inductive types. Conclusions reached include: "God does not exist" (strong atheism); "God almost certainly does not exist" (de facto atheism); "no one knows whether God exists" (agnosticism); "God exists, but this cannot be proven or disproven" (theism); and "God exists and this can be proven" (theism). There are numerous variations on these positions.
A recent argument for the existence of God is intelligent design, which asserts that "certain features of the universe and of living things are best explained by an intelligent cause, not an undirected process such as natural selection." It is a modern form of the traditional argument from design, modified to avoid specifying the nature or identity of the designer. Its primary proponents, all of whom are associated with the Discovery Institute, believe the designer to be the Abrahamic God.
Theologians and philosophers have ascribed a number of attributes to God, including omniscience, omnipotence, omnipresence, perfect goodness, divine simplicity, and eternal and necessary existence. God has been described as incorporeal, a personal being, the source of all moral obligation, and the greatest conceivable being existent. These attributes were all claimed to varying degrees by the early Jewish, Christian and Muslim scholars, including St Augustine, Al-Ghazali, and Maimonides.
Many medieval philosophers developed arguments for the existence of God, while attempting to comprehend the precise implications of God's attributes. Reconciling some of those attributes generated important philosophical problems and debates. For example, God's omniscience implies that God knows how free agents will choose to act. If God does know this, their apparent free will might be illusory, or foreknowledge does not imply predestination; and if God does not know it, God is not omniscient.
The last centuries of philosophy have seen vigorous questions regarding the arguments for God's existence raised by such philosophers as Immanuel Kant, David Hume and Antony Flew, although Kant held that the argument from morality was valid. The theist response has been either to contend, like Alvin Plantinga, that faith is "properly basic"; or to take, like Richard Swinburne, the evidentialist position. Some theists agree that none of the arguments for God's existence are compelling, but argue that faith is not a product of reason, but requires risk. There would be no risk, they say, if the arguments for God's existence were as solid as the laws of logic, a position summed up by Pascal as: "The heart has reasons which reason knows not of."
Most major religions hold God not as a metaphor, but a being that influences our day-to-day existences. Many believers allow for the existence of other, less powerful spiritual beings, and give them names such as angels, saints, djinni, demons, and devas.
Theism generally holds that God exists realistically, objectively, and independently of human thought; that God created and sustains everything; that God is omnipotent and eternal; personal and interacting with the universe through for example religious experience and the prayers of humans. It holds that God is both transcendent and immanent; thus, God is simultaneously infinite and in some way present in the affairs of the world. Not all theists subscribe to all the above propositions, but usually a fair number of them, c.f., family resemblance. Catholic theology holds that God is infinitely simple and is not involuntarily subject to time. Most theists hold that God is omnipotent, omniscient, and benevolent, although this belief raises questions about God's responsibility for evil and suffering in the world. Some theists ascribe to God a self-conscious or purposeful limiting of omnipotence, omniscience, or benevolence. Open Theism, by contrast, asserts that, due to the nature of time, God's omniscience does not mean the deity can predict the future. "Theism" is sometimes used to refer in general to any belief in a god or gods, i.e., monotheism or polytheism. 
Deism holds that God is wholly transcendent: God exists, but does not intervene in the world beyond what was necessary to create it. In this view, God is not anthropomorphic, and does not literally answer prayers or cause miracles to occur. Common in Deism is a belief that God has no interest in humanity and may not even be aware of humanity. Pandeism and Panendeism, respectively, combine Deism with the Pantheistic or Panentheistic beliefs discussed below.
See main article: Monotheism.
Some writers such as Karen Armstrong believe that the concept of monotheism sees a gradual development out of notions of henotheism and monolatrism. In the Ancient Near East, each city had a local patron deity, such as Shamash at Larsa or Sin at Ur. The first claims of global supremacy of a specific god date to the Late Bronze Age, with Akhenaten's Great Hymn to the Aten, and, depending on dating issues, Zoroaster's Gathas to Ahura Mazda. Currents of monism or monotheism emerge in Vedic India in the same period, with e.g. the Nasadiya Sukta. Philosophical monotheism and the associated concept of absolute good and evil emerges in Classical Antiquity, notably with Plato (c.f. Euthyphro dilemma), elaborated into the idea of The One in Neoplatonism.
According to The Oxford Companion To World Mythology (David Leeming, Oxford University Press, 2005, page 153), "The lack of cohesion among early Hebrews made monotheism - even monolatry, the exclusive worship of one god among many - an impossibility...And even then it can be argued that the firm establishment of monotheism in Judaism required the rabbinical or Talmudic process of the first century B.C.E. to the sixth century C.E.". In Islamic theology, a person who spontaneously "discovers" monotheism is called a ḥanīf, the original ḥanīf being Abraham.
Austrian anthropologist Wilhelm Schmidt in the 1910s postulated an Urmonotheismus, "original" or "primitive monotheism", a thesis now widely rejected in comparative religion but still occasionally defended in creationist circles.
Monotheists hold that there is only one god, and may claim that the one true god is worshiped in different religions under different names. The view that all theists actually worship the same god, whether they know it or not, is especially emphasized in Hinduism and Sikhism. Adherents of different religions, however, generally disagree as to how to best worship God and what is God's plan for mankind, if there is one. There are different approaches to reconciling the contradictory claims of monotheistic religions. One view is taken by exclusivists, who believe they are the chosen people or have exclusive access to absolute truth, generally through revelation or encounter with the Divine, which adherents of other religions do not. Another view is religious pluralism. A pluralist typically believes that his religion is the right one, but does not deny the partial truth of other religions. An example of a pluralist view in Christianity is supersessionism, i.e., the belief that one's religion is the fulfillment of previous religions. A third approach is relativistic inclusivism, where everybody is seen as equally right; an example in Christianity is universalism: the doctrine that salvation is eventually available for everyone. A fourth approach is syncretism, mixing different elements from different religion. An example of syncretism is the New Age movement.
Pantheism holds that God is the universe and the universe is God, whereas Panentheism holds that God contains, but is not identical to, the Universe; the distinctions between the two are subtle. It is also the view of the Liberal Catholic Church, Theosophy, some views of Hinduism except Vaishnavism which believes in panentheism, Sikhism, some divisions of Buddhism, some divisions of Neopaganism and Taoism, along with many varying denominations and individuals within denominations. Kabbalah, Jewish mysticism, paints a pantheistic/panentheistic view of God — which has wide acceptance in Hasidic Judaism, particularly from their founder The Baal Shem Tov — but only as an addition to the Jewish view of a personal god, not in the original pantheistic sense that denies or limits persona to God.
Dystheism, related to theodicy is a form of theism which holds that God is either not wholly good or is fully malevolent as a consequence of the problem of evil. One such example would be Satanism or the Devil. There is no known community of practicing dystheists.
Nontheism holds that the universe can be explained without any reference to the supernatural, or to a supernatural being. Some non-theists avoid the concept of God, whilst accepting that it is significant to many; other non-theists understand God as a symbol of human values and aspirations. Many schools of Buddhism may be considered non-theistic.
See also: Evolutionary origin of religions and Evolutionary psychology of religion. Stephen Jay Gould proposed an approach dividing the world of philosophy into what he called "non-overlapping magisteria" (NOMA). In this view, questions of the supernatural, such as those relating to the existence and nature of God, are non-empirical and are the proper domain of theology. The methods of science should then be used to answer any empirical question about the natural world, and theology should be used to answer questions about ultimate meaning and moral value. In this view, the perceived lack of any empirical footprint from the magisterium of the supernatural onto natural events makes science the sole player in the natural world. Another view, advanced by Richard Dawkins, is that the existence of God is an empirical question, on the grounds that "a universe with a god would be a completely different kind of universe from one without, and it would be a scientific difference."
See also: Anthropomorphism. Pascal Boyer argues that while there is a wide array of supernatural concepts found around the world, in general, supernatural beings tend to behave much like people. The construction of Gods and spirits like persons is one of the best known traits of religion. He cites examples from Greek Mythology which in his opinion, is more like a modern soap opera than other religious systems. Bertrand du Castel and Timothy Jurgensen demonstrate through formalization that Boyer's explanatory model matches physics' epistemology in positing not directly observable entities as intermediaries. Anthropologist Stewart Guthrie contends that people project human features onto non-human aspects of the world because it makes those aspects more familiar. Sigmund Freud also suggested that god concepts are projections of one's father.
Likewise, Emile Durkheim was one of the earliest to suggest that Gods represent an extension of human social life to include supernatural beings. In line with this reasoning, psychologist Matt Rossano contends that when humans began living in larger groups, they may have created gods as a means of enforcing morality. In small groups, morality can be enforced by social forces such as gossip or reputation. However it is much harder to enforce morality using social forces in much larger groups. He indicates that by including ever watchful gods and spirits, humans discovered an effective strategy for restraining selfishness and building more cooperative groups. 
See main article: List of religious populations. As of 2000, approximately 53% of the world's population identifies with one of the three Abrahamic religions (33% Christian, 20% Islam, <1% Judaism), 6% with Buddhism, 13% with Hinduism, 6% with traditional Chinese religion, 7% with various other religions, and less than 15% as non-religious. Most of these religious beliefs involve a god or gods.
. Hastings, James Rodney. James Hastings. John A Selbie. Encyclopedia of Religion and Ethics]]. Volume 4 of 24 ( Behistun (continued) to Bunyan.). Kessinger Publishing, LLC. Edinburgh. 2nd edition 1925-1940, reprint 1955, 2003. 1908-26. The encyclopedia will contain articles on all the religions of the world and on all the great systems of ethics. It will aim at containing articles on every religious belief or custom, and on every ethical movement, every philosophical idea, every moral practice.. 0-7661-3673-6. 03-05-2008. 476.
. J. J. C. Smart. John Haldane. Atheism and Theism. Blackwell Publishing. 2003. 0631232591. 8.
. The God Delusion. Richard Dawkins. 2006. Bantam Press. Great Britain. 0-618-68000-4.
. Computer Theology,. 0-9801821-1-5. Midori Press. Austin, Texas. 2008. Jurgensen, Timothy M.. Bertrand du Castel. 221–222.