God is often conceived as the supreme being and principal object of faith. In theism, God is the creator and sustainer of the universe. In deism, God is the creator (but not the sustainer) of the universe. In pantheism, God is the universe itself. Theologians have ascribed a variety of attributes to the many differentconceptions of God. Common among these are omniscience (infinite knowledge), omnipotence (unlimited power), omnipresence (present everywhere),omnibenevolence (perfect goodness), divine simplicity, and eternal and necessary existence. Monotheism is the belief in the existence of one God or in the oneness of God. God has also been conceived as being incorporeal (immaterial), a personal being, the source of all moral obligation, and the "greatest conceivable existent". Many notable medieval philosophers and modern philosophers have developed arguments for and against the existence of God.
There are many names for God, and different names are attached to different cultural ideas about who God is and what attributes he possesses. In the Hebrew Bible "I Am that I Am", and the "Tetragrammaton" YHVH are used as names of God, while Yahweh, and Jehovah are sometimes used in Christianity as vocalizations of YHVH. In Arabic, the name Allah ("the God") is used, and because of the predominance of Islam among Arab speakers, the name "Allah" has connotations with Islamic faith and culture. Muslims regard a multitude of titular names for God, while in Judaism it is common to refer to God by the titularnames Elohim or Adonai. In Hinduism, Brahman is often considered a monistic deity. Other religions have names for God, for instance, Baha in the Bahá'í Faith, Waheguru in Sikhism, and Ahura Mazda in Zoroastrianism.
Existence of God
Countless arguments have been proposed in attempt to prove the existence of God. Some of the most notable arguments are the 5 Ways of Aquinas, the Argument from Desire proposed byC.S. Lewis, the Lord, Lunatic or Liar Trilemma also by C.S. Lewis, and the Ontological Argument formulated both by St. Anselm and Descartes. Even among theists, these proofs are heavily debated. Some, such as the Ontological Argument, are highly controversial among theists. Aquinas spends a section of his treatise on God refuting St. Anselm's proof.
St. Anselm's approach was to define God as, "that than which nothing greater can be conceived". Famed pantheist philosopher Baruch Spinoza would later carry this idea to its extreme: “By God I understand a being absolutely infinite, i.e., a substance consisting of infinite attributes, of which each one expresses an eternal and infinite essence.” For Spinoza, the whole of the natural universe is made of one substance, God, or its equivalent, Nature. His proof for the existence of God was a variation of the Ontological argument.
Renowned physicist Stephen Hawking and co-author Leonard Mlodinow state in their book, The Grand Design, that it is reasonable to ask who or what created the universe, but if the answer is God, then the question has merely been deflected to that of who created God. In this view it is accepted that some entity exists that needs no creator, and that entity is called God. This is known as the first-cause argument for the existence of God. Both authors claim however, that it is possible to answer these questions purely within the realm of science, and without invoking any divine beings.
Some theologians, such as the scientist and theologian A.E. McGrath, argue that the existence of God is not a question that can be answered using the scientific method. AgnosticStephen Jay Gould argues that science and religion are not in conflict and do not overlap.
There are many philosophical issues concerning the existence of God. Some definitions of God are nonspecific, while others can be self-contradictory. Arguments for the existence of God typically include metaphysical, empirical, inductive, and subjective types, while others revolve around perceived 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 views that: "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" (weak theism); and that "God exists and this can be proven" (strong theism). There are numerous variations on these positions.