Many philosophers and scientists of the past have understood God as One Dynamic Substance. This is conducive to the pantheist conception of God as the Universe / Nature / Reality.
The term God is ordinarily used to designate a singular, universal Supreme Being.
However, there are countless variant definitions of this God. For example:
Many religious and philosophic systems consider God to be the creator of the universe.
Some traditions hold that the creator of the universe is also the sustainer of the universe (as in theism), while others argue that God is no longer involved in the world after creation (as in deism).
The common definition of God assumes omnipotence, omniscience and benevolence. However, not all systems hold that God is necessarily morally good. Others maintain that God is beyond the limited human understanding of morality. Negative theology argues that no true statements about attributes of God can be made at all, while agnostic positions argue that limited human understanding does not allow for any conclusive opinions on God whatsoever. Some mystical traditions ascribe limits to God's powers, arguing that God's supreme nature leaves no room for spontaneity.
The concept of a singular God is characteristic of monotheism, but there is no universal definition of monotheism. The differences between monotheism and polytheism vary among traditions.
Some concepts of God may include anthropomorphic attributes, gender and particular names, while others are purely transcendent or philosophic concepts.
Belief in God is often connected to concepts of absolute morality or truth, and sometimes to claims of exclusivity.
There are variations on defining God either as a person, or not as a person but as an ambiguous impersonal force. Also at stake are questions concerning the possibilities of human/God relations. There are countless variations in traditions of worship and/or appeasement of God.
Some espouse an exclusionist view, holding to one sole definition of God. Others hold an inclusionist view, accepting the possibility of more than one definition of God to be true at the same time.
There are also atheistic explanations for the concept of God that can include psychological and/or sociological factors.
Etymology of God
The word God continues Old English/Germanic god (guþ, gudis in Gothic, Gott in modern German). The original meaning and etymology of the Germanic word god have been hotly disputed, though most agree to a reconstructed Proto-Indo-European form hutom which is a passive perfect participle from the root *hu-, which likely meant "libation", "sacrifice". Compare:-
Vedic Sanskrit hu- = "to sacrifice".
Greek khu-, kheu- = "to pour".
Common Germanic strong verb geutan (Anglo-Saxon gēotan) = "to pour", English in-got.
The connection between these meanings is likely via the meaning "pour a libation". Another possible meaning of hutom is "invocation", related to Sanskrit huta.
The word God was used to represent Greek theos, Latin deus in Bible translations, first in the Gothic translation of the New Testament by Ulfilas.
History of monotheism
The religions widely thought of as monotheistic today are of relatively recent origin historically, although Eastern religions (notably religions of China and India) that have concepts of panentheism are difficult to classify along Western notions of monotheism vs. polytheism, and sometimes have claims of being very ancient, if not eternal.
In the Ancient Orient, many cities had their own local god, but this henotheistic worship of a single god did not imply denial of the existence of other gods. The Hebrew Ark of the Covenant adapted this practice to a nomadic lifestyle, paving their way for a singular God. The cult of the solar god Aten is often cited as the earliest known example of monotheism, but even if Akhetaten's hymn to Aten praises this god as omnipotent creator, worship of other gods beside him never ceased. Early examples of monotheism also include two late rigvedic hymns (10.129,130) to a Panentheistic creator god, Shri Rudram, a Vedic hymn to Rudra, an earlier aspect of Shiva, which expressed monistic theism, and is still chanted today, the Zoroastrian Ahuramazda and Chinese Shang Ti. The worship of polytheistic gods, on the other hand, is seen by many to predate monotheism, reaching back as far as the paleolithic. Today, monotheistic religions are dominant (mainly due to the missionary efforts of Christianity and Islam), but polytheism, and to a lesser extent also animism, survive.
Arguments for the existence of God
Arguments for or against the existence of God date back to classical times.
Ontological arguments argue God exists by necessity or definition — that God's existence can be determined from consideration of God's nature alone.
Cosmological arguments, or First Cause arguments, contend that the existence of the universe requires a self-sufficient prime mover, which can be called “God.”
Teleological arguments, or Arguments from Design, argue that the universe and its component parts display a complex and purposeful functionality that can only be the result of a designer, which can be called “God.”
Arguments from morality contend that human recognition of 'good' and 'evil' can only come from God, and therefore implies the existence of God.
Arguments against the existence of God
Alternately, there are a variety of arguments against the existence of God.
The problem of evil argues that the existence of suffering is inconsistent with an omnipotent, omniscient and benevolent God.
The argument from inconsistent revelations argues the diversity of different religious beliefs makes the 'truth' of any particular viewpoint on God highly improbable.
Incompatible-properties arguments contend that many of the properties often assigned to God are logically inconsistent with each other.
Burden of proof is the logical position that the existence of a God is an extraordinary claim that should be rejected until proven to exist by extraordinary evidence.
Argument against the Cosmological argument: The universe is a cause and effect system. Therefore, it is logical that the universe had a cause. One can extend the argument, however, as, If God created the universe who created God? In other words, if everything must have a cause then what or who came before God? If God could exist without a cause then so can the universe. That is, if God can be self-caused or exist w/out a cause (a priori), and then have caused the universe, so, is the argument that the universe may be self-caused or exist w/out a cause (a priori), and therefore be not caused by God, equally valid. (In fact, by Occam's Razor a.k.a. minimum message length, being a simpler explanation, the latter possibility is a more reasonable/reliable/usefull model. This relates to the burden of proof argument.)
Argument against a logical definition of God: The definition of God assumes omnipotence. Logically, if the term "omnipotence" means "able to do all things", an omnipotent being can create another being more powerful than itself. But this is a paradox. Therefore, an omnipotent being cannot exist.
Fideism maintains that all attempted proofs and disproofs of God's existence are misguided, as belief in God must depend on faith rather than any rational arguments or proofs. This argument makes the existence of God a spiritual "question" as opposed to an intellectual one. Fideists often quote scripture as support for their claim, such as Hebrews 11:6.
Conceptions of God
Jewish, Christian and Muslim conceptions
Judaism, Christianity and Islam see God as a being who created the world and rules over the universe. God is usually held to have the properties of holiness (separate from sin and incorruptible), justness (fair, right, and true in all His judgements), sovereignty (unthwartable in His will), omnipotence (all-powerful), omniscience (all-knowing), omnibenevolence (all-loving), and omnipresence (all-present).
Jews, Christians and Muslims often conceive of God as a personal God, with a will and personality. However, many medieval rationalist philosophers of these religions felt that one should not view God as personal, and that such personal descriptions of God are only meant as metaphors. Some within these three faiths still accept these views as valid, although many of the laity today do not have a wide awareness of them.
In Eastern Christianity, it remains essential that God be personal; hence it speaks of the three persons of the Trinity. It also emphasizes that God has a will, and that God the Son has two wills, divine and human, though these are never in conflict. The personhood of God and of all human people is essential to the concept of theosis or deification.
Biblical definition of God
The Hebrew Bible (Old Testament) characterizes God by these attributes: "The LORD, the LORD God, merciful and gracious, slow to anger, and abounding in steadfast love and faithfulness, keeping steadfast love for thousands, forgiving iniquity and transgression and sin, but who will by no means clear the guilty, visiting the iniquity of the fathers upon the children and the children's children, to the third and the fourth generation." (Exodus 34:6–7)
The Hebrew Bible contains no systematic theology: No attempt is made to give a philosophical or rigorous definition of God, nor of how God acts in the world. It does not explicitly describe God's nature, exemplified by God's assertion in Exodus that "you cannot see my face; for man shall not see me and live". Nowhere in the Hebrew Bible are the words omnipotent, omniscient, or omnibenevolent used to define God in a systematic sense.
Although Scripture does not describe God systematically, however, it does provide a poetic depiction of God and His relationship with people. According to the biblical historian Yehezkal Kaufmann, the essential innovation of Biblical theology was to posit a God that cares about people, and that cares about whether people care about Him. Most people believe that the Bible should be viewed as humanity's view of God, but theologian Abraham Joshua Heschel described the Biblical God as "anthropopathic", which means that one should read the Bible as God's view of humanity, and not as humanity's view of God.
Similarly, the New Testament contains no systematic theology: no attempt is made to give a philosophical or rigorous definition of God, nor of how God acts in the world. The New Testament does, however, provide an implicit theology as it teaches that God became human while remaining fully God, in the person of Jesus, and that he subsequently sent the Holy Spirit. In this view, God becomes someone that can be seen and touched, and may speak and act in a manner easily perceived by humans, while also remaining transcendent and invisible. This appears to be a radical departure from the concepts of God found in Hebrew Bible. The New Testament's statements regarding the nature of God were eventually developed into the doctrine of the Trinity.
Kabbalistic definition of God
Kabbalah (Jewish mysticism) teaches that God is neither matter nor spirit. Rather God is the creator of both, but is himself neither. But if God is so different from his creation, how can there be any interaction between the Creator and the created? This question prompted Kabbalists to envision two aspects of God, (a) God himself, who in the end is unknowable, and (b) the revealed aspect of God who created the universe, preserves the universe, and interacts with mankind in a personal way. Kabbalists believe that these two aspects are not contradictory but complement one another.
God as Unity or Trinity
Jews, Muslims, and a small fraction of Christians are unitarian monotheists. The vast majority of Christians have been and still are Trinitarian monotheists.
Unitarian monotheists hold that there is only one "person" (so to speak), or one basic substance, in God. Some adherents of this position consider Trinitarianism to be a form of polytheism.
Trinitarian monotheists believe in one God that exists as three distinct persons who share the same substance/essence; the Christian version of this is called the Trinity, the Hindu version Trimurti. Trinitarians hold that the three persons have the same purpose, holiness, and sovereignty, and therefore each can be worshiped as God, without violating the idea that there is only one God to which worship belongs.
Mormons believe that there are three separate divine personages. One of these personages is a spirit without a body referred to as the Holy Ghost. The other two personages are spirits with perfected or glorified (often called celestial) bodies referred to as Heavenly Father (or less commonly "Elohim") and his son, Jesus Christ. Mormons hold that God is a Holy Man who advanced to his divine status through a repeatable process of progression. They believe that by following their religion's teachings, humans can literally become gods (sometimes phrased as "become like Heavenly Father") at some point after death and resurrection; this is also called Exaltation.
Rastafarians believe that Haile Selassie is both God the Father and God the Son, made manifest in human flesh as the reincarnation of Jesus, while the Holy Spirit is seen to dwell within all believers (of Rastafari), and within all people (believed by some).
Hasidic Jews hold that there are ten Sefirot (emanations) of God. Each of these are more distinct than a characteristic, but less distinct than a separate personage.
Monism is the metaphysical position that all is of one essential essence, substance or energy, that being a pantheist, or panentheist, immanent God. Monism can be inclusive of other interpretations of God.
Dualism is the idea of two, nearly equal divine entities, one being the good God, and the other being an evil god, or Satan. All beings are under the influence of one side, or the other, if they know it or not. Zoroastrianism is an example of dualism.
Aristotelian definition of God
In his Metaphysics, Aristotle discusses the meaning of "being as being". Aristotle holds that "being" primarily refers to the Unmoved Movers, and assigned one of these to each movement in the heavens. Each Unmoved Mover continuously contemplates its own contemplation, and everything that fits the second meaning of "being" by having its source of motion in itself, moves because the knowledge of its Mover causes it to emulate this Mover (or should).
Arguably, Eastern conceptions of The Ultimate (this, too, has many different names) are not conceptions of a personal divinity, though certain Western conceptions of what is at least called "God" (e.g., Spinoza's pantheistic conception and various kinds of mysticism) resemble Eastern conceptions of The Ultimate.
Philologically, Gk. theos is said to be akin to Zeus, the chief god in Greek mythology, who has Dios in a genitive form. L. Diespiter means Jupiter, chief god in L. mythology, dies + pater, day + father. In Skr. deva is a god, as derived from the root div, heaven, and diu denoting day, shine and brightness (L. niter).
Hindu Conceptions of God
In Shaivism and Vaishnavism, Hindus believe that God, whether in the form of Shiva or Vishnu has six attributes. However, the actual number of auspicious qualities of God, are countless, with the following six qualities being the most important.
The number six is invariably given, but the individual attributes variously listed are Jnana (Omniscience), defined as the power to know about all beings simultaneously; Aishvarya (Sovereignty), which consists in unchallenged rule over all; Shakti (Energy), or power, which is the capacity to make the impossible possible; Bala (Strength), which is the capacity to support everything by His will and without any fatigue; Virya (Vigour), or valour which indicates the power to retain immateriality as the Supreme Being in spite of being the material cause of mutable creations; and Tejas (Splendour), which expresses His self-sufficiency and the capacity to overpower everything by His spiritual effulgence.; cited from Bhakti Schools of Vedanta, by Swami Tapasyananda.
Other six characteristics are listed as Jnana (Omniscience), Vairagya (Dispassion), Yasas (Fame), Aisvarya (Sovereignty), Sri (Glory), Dharma (Righteousness). Other important qualities attributed to God are Gambhirya (inestimatble grandeur), Audarya (generosity), and Karunya (compassion).
Chanted prayers, or mantras, are central to Hindu worship. Among the most chanted mantras in Hinduism are the Vishnu sahasranama (a prayer to Vishnu that dates from the time of the Mahabharata and describes Him as the Universal Brahman), Shri Rudram (a Vedic hymn to Rudra, an earlier aspect of Shiva that also describes Him as Brahman) and the Gayatri mantra, (another Vedic hymn that initially was meant as a prayer to the Sun, an aspect of Brahman but has other interpretations. It is now interpreted as a prayer to the impersonal absolute Brahman). Another famous hymn, Lalitha Sahasranama, describes the 1000 names of Devi, worshipped as God the Divine Mother, or God's Shakti or Power personified by Hindus.
Modern views of God
The mathematician Georg Cantor identified God with the mathematical concept of the Absolute Infinite.
Kurt Gödel's "ontological proof" is a mathematical formulation of Saint Anselm's ontological argument.
Process philosophy and Open Theism definition of God
Process theology is a school of thought influenced by the metaphysical process philosophy of Alfred North Whitehead (1861–1947). Open Theism, a theological movement that began in the 1990s, is similar, but not identical, to Process theology.
In both views, God is not omnipotent in the classical sense of a coercive being. Reality is not made up of material substances that endure through time, but serially-ordered events, which are experiential in nature. The universe is characterized by process and change carried out by the agents of free will. Self-determination characterizes everything in the universe, not just human beings. God and creatures co-create. God cannot force anything to happen, but rather only influence the exercise of this universal free will by offering possibilities. See the entries on process theology, panentheism, and Open Theism.
Similar to this theory is the belief or aspiration that humans will create a God entity, emerging from an artificial intelligence. Arthur C. Clarke, a science fiction writer, said in an interview that: It may be that our role on this planet is not to worship God, but to create him.
Another variant on this hypothesis is that humanity or a segment of humanity will create or evolve into a posthuman God by itself; for some examples, see cosmotheism, transhumanism, technological singularity.
The philosopher Michel Henry defines God in a phenomenological point of view. He says : God is Life, he is the essence of Life, or, if we prefere, the essence of Life is God. Saying this we already know what is God, we know it not by the effect of a learning or of some knowledge, we don’t know it by the thought, on the background of the truth of the world ; we know it and we can know it only in and by the Life itself. We can know it only in God.