What Is Islam? Beliefs, Meaning and Core Teachings

Published 11 Aug 2026 • 8 min read

Islam is a monotheistic religion built on belief in one God, revealed in its final form to the Prophet Muhammad ﷺ in 7th-century Arabia. With close to two billion followers, it is the world's second-largest religion. The word Islam means submission to God, and a Muslim is a person who submits to Him. This article explains what Islam is, what Muslims believe, its holy book, and its core teachings.

The Core Idea of Islam

The central teaching of Islam is Tawhid — the absolute oneness of God. Muslims believe in a single, eternal Creator, called Allah in Arabic (the same word Arabic-speaking Jews and Christians use for God). God has no partner, no equal and no offspring; He alone is worshipped. Everything else in Islam — its beliefs, worship and ethics — flows from this single principle. Islam presents itself not as a brand-new religion but as the final expression of the same monotheism taught by earlier prophets such as Abraham, Moses and Jesus.

The Six Articles of Faith

Islamic belief (iman) rests on six core articles. A Muslim believes in:

  • God (Allah) — one, eternal, all-powerful and merciful, the Creator of everything that exists.
  • The Angels — beings created from light who carry out God's commands, such as Gabriel, who brought the revelation.
  • The Revealed Books — the scriptures God sent, including the Torah, the Psalms and the Gospel, and finally the Quran, which Muslims believe completes and safeguards the earlier message.
  • The Prophets — the long line of messengers from Adam to Muhammad ﷺ, sent to guide humanity to God.
  • The Last Day — the Day of Judgement, when every person will be raised and held accountable for their deeds.
  • Divine Decree (Qadar) — that God has knowledge and power over all things, and nothing happens outside His will.

Is Islam Monotheistic?

Yes — Islam is strictly monotheistic. Its most fundamental belief is that there is only one God, with no partners, no divine family and no lesser gods. This is captured in the first half of the Muslim declaration of faith: "There is no god but God." Associating partners with God (shirk) is regarded as the gravest sin in Islam. In this, Islam stands alongside Judaism and Christianity as one of the three great Abrahamic faiths, though it emphasises God's absolute oneness in a particularly uncompromising way.

The Quran: Islam's Holy Book

The holy book of Islam is the Quran. Muslims believe it is the literal word of God, revealed to Muhammad ﷺ through the angel Gabriel over about 23 years, and preserved unchanged ever since in its original Arabic. Alongside the Quran, Muslims follow the Sunnah — the recorded teachings, sayings and example of the Prophet ﷺ, gathered in reports known as hadith. Together, the Quran and the Sunnah are the two primary sources of Islamic belief, worship and law.

Prophets in Islam — and Does Islam Believe in Jesus?

Muslims believe God sent prophets to every people throughout history, beginning with Adam and including Noah, Abraham, Moses and Jesus, with Muhammad ﷺ as the final prophet. Islam holds all of them in deep respect and does not allow any to be mocked or belittled.

Jesus (Isa in Arabic) holds an especially honoured place. Muslims believe he was a mighty prophet and the Messiah, born miraculously of the Virgin Mary (Maryam) — who has an entire chapter of the Quran named after her — and that he performed miracles by God's permission. However, Muslims do not believe Jesus was divine or the son of God; in Islam he is a revered human prophet, not part of a trinity. Mainstream Islamic belief also holds that he was not crucified but raised up by God, and that he will return before the end of time. Islam therefore deeply honours Jesus while differing from Christianity on his nature.

The Five Pillars: How Muslims Worship

If the six articles are what a Muslim believes, the Five Pillars are what a Muslim does. They are the five core acts of worship that frame a Muslim's life: the declaration of faith (Shahada), the five daily prayers (Salah), giving a set share of wealth to the poor (Zakat), fasting in the month of Ramadan (Sawm), and the pilgrimage to Mecca (Hajj) for those able to make it. Each pillar links personal devotion to a worldwide community of believers.

How Muslims Live

Beyond belief and worship, Islam offers a way of life. It teaches honesty, charity, kindness to parents and neighbours, justice and modesty, and it guides everyday matters such as food (halal), family and finance. For Muslims, faith is not confined to ritual but is meant to shape character and conduct in daily life — treating good manners and service to others as part of worship itself.

How Islam Relates to Christianity and Judaism

Islam, Christianity and Judaism are the three great Abrahamic faiths, all tracing their heritage to the Prophet Abraham and all believing in one God. Islam shares many figures with them — Adam, Noah, Abraham, Moses, David and Jesus are all honoured as prophets — and it respects the Torah and the Gospel as scriptures originally revealed by God. Where Islam differs is in its insistence on God's absolute oneness — rejecting the Trinity and the divinity of Jesus — in its belief that Muhammad ﷺ is the final prophet, and in its view of the Quran as God's last and perfectly preserved revelation.

Sunni and Shia: The Two Main Branches

Most of the world's Muslims — around 85 to 90 percent — are Sunni, while roughly 10 to 15 percent are Shia. The division has its roots in a 7th-century disagreement over who should lead the community after the Prophet Muhammad ﷺ, rather than in the core beliefs themselves. Sunnis and Shias share the same God, the same Quran, the same Prophet, and the same fundamental practices such as prayer and fasting; they differ mainly in matters of religious authority, law and certain points of history. Both belong to the wider Muslim community.

Islam at a Glance

  • Meaning: submission to the one God.
  • God: Allah — one, with no partner.
  • Holy book: the Quran, together with the Sunnah of the Prophet ﷺ.
  • Final prophet: Muhammad ﷺ (c. 570–632 CE).
  • Core beliefs: the six articles of faith.
  • Core practices: the Five Pillars.
  • Followers: close to two billion — the world's second-largest religion.

Frequently Asked Questions

What do Muslims believe in?

Muslims believe in one God (Allah), His angels, His revealed books, His prophets from Adam to Muhammad ﷺ, the Day of Judgement, and divine decree — the six articles of faith.

Is Islam monotheistic or polytheistic?

Islam is strictly monotheistic. It teaches belief in a single God with no partners, and considers associating anything with God the gravest sin.

Does Islam believe in Jesus?

Yes. Muslims honour Jesus as a great prophet and the Messiah, born of the Virgin Mary, but they do not regard him as divine or as the son of God.

What is the holy book of Islam?

The Quran, which Muslims believe is the word of God revealed to Muhammad ﷺ and preserved in its original Arabic, followed alongside the Prophet's Sunnah.

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