What is Islam? Beliefs, the Quran and the Five Pillars

Islam is the religion of people who submit to one God, Allah, as he was revealed, Muslims believe, through a line of prophets that ended with Muhammad in 7th-century Arabia. The word islam means "submission" in Arabic, and a Muslim is "one who submits". Its scripture is the Quran, and its practice rests on five duties, the Five Pillars. Muslims made up about a quarter of the world's population in 2020.

In short

• Muslims believe in one God, in prophets from Adam and Abraham to Moses, Jesus and Muhammad, the last of them, and in a Day of Judgment.
• The Quran is, for Muslims, God's own word, revealed to Muhammad in Arabic; the hadith record what Muhammad said and did.
• The Five Pillars are the declaration of faith, daily prayer, almsgiving, the fast of Ramadan and the pilgrimage to Mecca.

What do Muslims believe?

The heart of Islam is tawhid, the oneness of God. God has no partner, no equal and no son, and nothing in creation may be worshipped beside him. Allah is simply the Arabic word for God, used also by Arabic-speaking Christians. Sunni Muslims usually list six articles of faith:

1. God, one and unique, creator of everything.
2. Angels, who carry God's messages; Jibril (Gabriel) brought the Quran to Muhammad.
3. Revealed books, including the Torah given to Moses, the Psalms to David, the Gospel to Jesus and, last, the Quran.
4. Prophets, from Adam through Noah, Abraham, Moses and Jesus to Muhammad, the "seal of the prophets".
5. The Day of Judgment, when the dead will be raised and judged, and enter paradise or hell.
6. God's decree: everything happens within God's knowledge and will.

Muslims see Islam not as a new religion but as the original faith of Abraham, which, they believe, earlier communities received and partly altered. That is why the Quran honors figures known from Judaism and Christianity. It calls Jews and Christians "People of the Book", and gives Jesus, whom it calls Isa, a special place as prophet and Messiah, though not as God's son; the differences are set out in who Jesus was.

What are the Quran, the hadith and sharia?

The Quran is the scripture of Islam, in 114 chapters called suras. Muslims believe it was revealed to Muhammad over about 23 years, from about 610 until his death in 632, and that it is God's word itself, not Muhammad's. It was gathered into one written text under the third caliph, Uthman, around 650. Because Muslims hold the revelation to be Arabic, translations are treated as interpretations, and Muslims everywhere pray in Arabic.

The hadith are reports of what Muhammad said, did and approved, each passed down with a chain of narrators. Scholars graded them for reliability, and Sunni Muslims hold six collections in highest regard, above all those of al-Bukhari and Muslim, compiled in the 9th century. Shia Muslims have their own collections, which include reports from their imams. The life of the Prophet Muhammad is known through these and through the early biographies.

Sharia, literally "the path to the watering place", is God's guidance for the whole of life. Human scholars work it out in fiqh, jurisprudence, from the Quran, the hadith, scholarly consensus and reasoning by analogy, and most of it concerns prayer, fasting, food, marriage, inheritance, business and ethics, not criminal punishment, which is what the word often calls to mind in English (BBC Religions). Sunni Islam has four main schools of law, the Hanafi, Maliki, Shafi'i and Hanbali, and most Shia follow the Ja'fari school. Muslims differ widely on whether and how sharia should shape a state's laws.

What are the Five Pillars, and how are they practiced?

The Five Pillars are the duties every adult Muslim who is able is expected to keep.

Pillar	What it is	How often
Shahada	The declaration: "There is no god but God, and Muhammad is the messenger of God"	Said with sincerity, it makes a person Muslim; repeated in every prayer
Salat	Ritual prayer, facing the Kaaba in Mecca, after washing	Five times a day: dawn, midday, afternoon, sunset and night
Zakat	Almsgiving: usually 2.5% of savings held for a year above a minimum, the nisab	Once a year
Sawm	Fasting from dawn to sunset	The month of Ramadan
Hajj	Pilgrimage to Mecca	Once in a lifetime, for those who can afford it and are able

Zakat is easy to see with numbers. Say a woman has held $12,000 in savings for a full lunar year, above the nisab, which is pegged to the value of 85 grams of gold or 595 grams of silver. Her zakat is 2.5% of $12,000, or $300, paid to people the Quran names as eligible, such as the poor and those in debt. It is a duty, not a voluntary charity, which is called sadaqa and given on top.

A day in Ramadan

Ramadan is the ninth month of the Islamic calendar, the month in which, Muslims believe, the Quran was first revealed. The calendar is lunar, so Ramadan comes about 11 days earlier each solar year and moves through all the seasons over about 33 years. A day of the fast runs like this:

1. Before dawn, a meal, suhur, and the dawn prayer.
2. Through the day, no food, no drink, not even water, no smoking and no sex. Fasting is also meant to discipline the tongue and temper.
3. At sunset, the fast is broken with iftar, traditionally with dates and water, followed by the sunset prayer and a meal often shared with family, neighbors and strangers.
4. At night, many attend extra prayers at the mosque, the tarawih, and recite the Quran, aiming to finish it during the month.

Children, the ill, travelers, the elderly, and women who are pregnant, nursing or menstruating are excused, and many make up the days later or feed a poor person for each day missed. The month ends with Eid al-Fitr, the festival of breaking the fast.

The Hajj

The Hajj takes place over five or six days in the 12th month, Dhu al-Hijjah, and follows a set order (BBC Religions). Pilgrims enter a state of consecration, ihram, in which men wear two plain white cloths, so that rich and poor look alike. They walk seven times around the Kaaba, and seven times between the hills of Safa and Marwa, recalling Hagar's search for water for her son Ishmael. On the 9th they stand in prayer on the plain of Arafat from noon to sunset, the high point of the Hajj. Over the next days they throw pebbles at three pillars at Mina that represent the devil's temptation of Abraham, and an animal is sacrificed in memory of Abraham's readiness to sacrifice his son. Muslims everywhere mark that day as Eid al-Adha.

Why are there Sunni and Shia Muslims?

The split began with a question of leadership after Muhammad died in 632 (BBC Religions). Most of the community accepted Abu Bakr, his close companion and father-in-law, as the first caliph, or successor. A smaller group held that Muhammad had appointed his cousin and son-in-law, Ali, and that leadership belonged to Ali and his descendants. They became the Shi'at Ali, "the party of Ali", or Shia. Ali did become the fourth caliph, but was assassinated in 661, and in 680 his son Husayn and a small band were killed at Karbala, in today's Iraq, by the army of the caliph Yazid. Shia Muslims mourn Husayn each year at Ashura.

Over time the political dispute grew religious differences: Shia Muslims follow a line of imams descended from Ali, whom most of them, the Twelvers, count as twelve, and give their scholars greater authority to interpret. Both share the Quran, the Five Pillars and the core beliefs. Pew Research Center estimated in 2009 that 87% to 90% of Muslims are Sunni and 10% to 13% Shia, most of the Shia living in Iran, Pakistan, India and Iraq (Pew Research Center). Sufism, Islam's mystical tradition, runs across both.

How many Muslims are there, and where?

Pew Research Center put Muslims at 25.6% of the world's population in 2020, about 2 billion people, and found Islam the fastest-growing major religion between 2010 and 2020, mainly because Muslims are young and have more children on average, not through conversion (Pew Research Center, 2025). Most Muslims are not Arab: about six in ten live in the Asia-Pacific region, and Indonesia has more Muslims than any other country. That spread is also a reminder that customs vary greatly from one Muslim society to another, from Senegal to Bosnia to Malaysia.

For many centuries the most powerful Muslim state was the Ottoman Empire, whose sultans claimed the title of caliph; Turkey abolished the caliphate in 1924. Islam is the third of the faiths that trace themselves to Abraham, after Judaism and Christianity, and how these traditions fit the scholars' idea of religion is a question of its own.

Check yourself

• Without looking back, name the Five Pillars and say what each asks of a Muslim.
• Why do Muslims see Islam as the faith of Abraham rather than a new religion?
• What question about leadership divided Sunni and Shia Muslims, and when?

Sources

• How the Global Religious Landscape Changed From 2010 to 2020 — Pew Research Center, 2025
• Mapping the Global Muslim Population — Pew Research Center, 2009
• Sharia — BBC Religions, 2009
• Hajj: pilgrimage to Mecca — BBC Religions, 2009
• Sunni and Shi'a — BBC Religions, 2009
• Islam — Wikipedia