Monotheism: belief in one God

The word combines the Greek monos, “single,” and theos, “god.” It was coined in the seventeenth century by English writers, notably the philosopher Henry More, to classify religions. Like many such terms, it is a modern category applied to older traditions, and the traditions themselves use their own language, such as tawhid in Islam or the Shema in Judaism.

The Hebrew Bible proclaims that the God of Israel is the one God, creator of heaven and earth. The Shema, “Hear, O Israel: the Lord is our God, the Lord is one,” is Judaism’s central declaration. Jewish tradition rejects any division in God, any physical form and any intermediary who shares God’s divinity.

Many scholars think Israelite religion developed toward strict monotheism over time. Some early biblical texts speak of other gods existing while commanding Israel to worship only its own God, a stance scholars call monolatry. By the later prophets, such as Second Isaiah, the claim that no other god exists is explicit.

Christianity inherits Jewish monotheism and affirms that there is one God. Most Christians understand this God as a Trinity: Father, Son and Holy Spirit, three persons sharing one divine being. Christians regard the Trinity as monotheistic; Jews and Muslims have generally regarded it as compromising God’s unity. This disagreement is one of the most important differences among the three Abrahamic religions.

Islam’s central teaching is tawhid, the absolute oneness of God. The Quran’s short chapter Al-Ikhlas declares that God is one, eternal, neither begets nor is begotten, and has no equal. Associating partners with God, shirk, is considered the gravest sin. Islamic theology affirms God’s unity in being, in lordship and in the exclusive right to be worshipped.

Sikhism begins its scripture with Ik Oankar, “one Creator,” and teaches devotion to one formless Divine reality. The Baha’i faith teaches one God who has revealed himself progressively through messengers of many religions. Zoroastrianism, an ancient Persian religion, centres on the wise lord Ahura Mazda and is often cited as an early form of monotheism, though scholars debate its dualistic elements.

Hinduism does not fit neatly into the categories of monotheism or polytheism. Many Hindus worship several deities, yet many also understand them as forms of one ultimate reality, Brahman, or as manifestations of a supreme God such as Vishnu or Shiva. Scholars sometimes use terms like henotheism, worship of one god without denying others, or monism, the belief that all reality is ultimately one, to describe different Hindu views.

Monotheistic traditions differ on whether God is personal or impersonal, whether God is wholly separate from the world (transcendent) or present within it (immanent), and how God can be known. Philosophers distinguish monotheism from pantheism, which identifies God with the universe, and from deism, which holds that a creator does not intervene in the world.

Monotheistic traditions often link belief in one God to a single moral order: if one God created all people, then all people share dignity and are accountable to the same standard of justice. Prophetic traditions in Judaism, Christianity and Islam use this idea to criticize injustice and idolatry, including the worship of wealth or power.

Monotheistic traditions often include beings other than God, such as angels, saints, prophets or spirits. Their place is carefully defined: angels in Judaism, Christianity and Islam are created servants of God, not gods. Catholic and Orthodox Christians ask saints to pray for them but distinguish this veneration from the worship owed to God alone. Islam strongly guards against any practice that could treat a created being as a partner of God.

Monotheism is belief in one God. It is central to Judaism, Christianity and Islam and important in Sikhism and other faiths. These traditions agree that God is one but understand that oneness differently, most notably in the Christian doctrine of the Trinity and in Hindu traditions that see many deities as forms of one reality.