God the Sustainer in the context of "Classical theism"

In Christianity, God is the eternal, supreme being who created and preserves all things. Christians believe in a monotheistic conception of God, which is both transcendent (wholly independent of, and removed from, the material universe) and immanent (involved in the material universe). Christians believe in a singular God that exists in a Trinity, which consists of three Persons: God the Father, God the Son, and God the Holy Spirit. Christian teachings on the transcendence, immanence, and involvement of God in the world and his love for humanity exclude the belief that God is of the same substance as the created universe (rejection of pantheism) but accept that God the Son assumed hypostatically united human nature, thus becoming man in a unique event known as "the Incarnation".

Early Christian views of God were expressed in the Pauline epistles and the early Christian creeds, which proclaimed one God and the divinity of Jesus. Although some early sects of Christianity, such as the Jewish-Christian Ebionites, protested against the deification of Jesus, the concept of Jesus being one with God was accepted by the majority of Gentile Christians. This formed one aspect of the split of early Christianity and Judaism, as Gentile Christian views of God began to diverge from the traditional Jewish teachings of the time.

In theology, divine providence, or simply providence, is God's intervention in the universe. The term Divine Providence (usually capitalized) is also used as a title of God. A distinction is usually made between "general providence", which refers to God's continuous upholding of the existence and natural order of the universe, and "special providence", which refers to God's extraordinary intervention in the life of people. Miracles and even retribution generally fall in the latter category.

In Islam, God (Arabic: ٱللَّٰه, romanized: Allāh, contraction of ٱلْإِلَٰه al-’ilāh, lit. 'the god', or Arabic: رب, romanized: Rabb, lit. 'lord') is seen as the creator and sustainer of the universe, who lives eternally. God is conceived as a perfect, singular, immortal, omnipotent, and omniscient deity, completely infinite in all of his attributes. Islam further emphasizes that God is most merciful. The Islamic concept of God is variously described as monotheistic, panentheistic, and monistic.

The Islamic concept of tawhid (unification) emphasises that God is absolutely pure and free from association or partnership with other beings, which means attributing the powers and qualities of God to his creation, and vice versa. In Islam, God is never portrayed in any image. The Quran specifically forbids ascribing partners to share his singular sovereignty, as he is considered to be the absolute one without a second, indivisible, and incomparable being, who is similar to nothing, and nothing is comparable to him. Thus, God is absolutely transcendent, unique and utterly other than anything in or of the world as to be beyond all forms of human thought and expression. The briefest and the most comprehensive description of God in the Quran is found in Surat al-Ikhlas.

In monotheistic religious belief systems, God is usually viewed as the supreme being, creator, and principal object of faith. In polytheistic belief, a god is "a spirit or being believed to have created, or for controlling some part of the universe or life, for which such a deity is often worshipped". Belief in the existence of at least one deity, who may interact with the world, is called theism.

Conceptions of God vary considerably. Many notable theologians and philosophers have developed arguments for and against the existence of God. Atheism rejects the belief in any deity. Agnosticism is the belief that the existence of God is unknown or unknowable. Some theists view knowledge concerning God as derived from faith. God is often conceived as the greatest entity in existence. God is often believed to be the cause of all things and so is seen as the creator, sustainer, and ruler of the universe. God is often thought of as incorporeal and independent of the material creation, which was initially called pantheism, although church theologians, in attacking pantheism, described pantheism as the belief that God is the material universe itself. God is sometimes seen as omnibenevolent, while deism holds that God is not involved with humanity apart from creation.