Monotheism (from Greek μόνος, monos, "single", and θεός, theos, "god") is the belief in the existence of one and only one god. Monotheism is characteristic of numerous religions, including the Baha'i Faith, Christianity, Druzism, Hinduism, Islam, Judaism, Samaritanism, Sikhism and Zoroastrianism.
It is difficult to delineate monotheism from beliefs such as pantheism and monism as in the Advaita traditions of Hinduism. Some scholars, such as Wilhelm Schmidt, argued for primeval monotheism: a monotheistic Urreligion, from which polytheistic religions developed. Other forms of monotheism includes unitarianism and deism.
As they vehemently profess a concept of strict monotheism, or unitarianism, Judaism and Islam adamantly reject various distinctions, particularly that the God of Israel, whom Muslims identify as Allah, can be associated with the Christian notion of a triune Godhead and the doctrine of Jesus as God incarnate.
Vishnu (Sanskrit विष्णु Viṣṇu) is the Supreme god in the Vaishnavite tradition of Hinduism. Smarta followers of Adi Shankara, among others, venerate Vishnu as one of the five primary forms of God.
The Vishnu Sahasranama declares Vishnu as Paramatman (supreme soul) and Parameshwara (supreme God). It describes Vishnu as the All-Pervading essence of all beings, the master of—and beyond—the past, present and future, one who supports, sustains and governs the Universe and originates and develops all elements within. Vishnu governs the aspect of preservation and sustenance of the universe, so he is called "Preserver of the universe".
In the Puranas, Vishnu is described as having the divine colour of water filled clouds, four-armed, holding a lotus, mace, shankha (conch) and chakra (wheel). Vishnu is also described in the Bhagavad Gita as having a 'Universal Form' (Vishvarupa) which is beyond the ordinary limits of human perception or imagination.