Why do people believe the Quran is from God?

Because many people find the Quran speaks to them in a way no human book does. Muslims point to its language, its consistent message, the way it has been preserved word for word, and the life of the Prophet ﷺ who received it. None of these is a lab test; for most people belief grows from reading it and reflecting on it.

The language and style

The Quran was revealed in Arabic, and Arabic speakers, including those who rejected the message at the time, were struck by its style. It is neither ordinary prose nor poetry. The Quran itself challenges doubters to bring something like it:

وَإِن كُنتُمْ فِى رَيْبٍ مِّمَّا نَزَّلْنَا عَلَىٰ عَبْدِنَا فَأْتُوا۟ بِسُورَةٍ مِّن مِّثْلِهِۦ "And if you are in doubt about what We have revealed to Our servant, then produce a sûrah like it" Quran 2:23

If you read it in translation, you will miss much of this beauty. Many new Muslims say it only clicked when they heard it recited. See Which English translation of the Quran should I read?

A message that holds together

The Quran was revealed gradually over about 23 years, in different circumstances, yet it keeps the same core message: one God, accountability, mercy, justice and good character. It invites you to think rather than simply accept:

أَفَلَا يَتَدَبَّرُونَ ٱلْقُرْءَانَ ۚ وَلَوْ كَانَ مِنْ عِندِ غَيْرِ ٱللَّهِ لَوَجَدُوا۟ فِيهِ ٱخْتِلَـٰفًا كَثِيرًا "Do they not then reflect on the Quran? Had it been from anyone other than Allah, they would have certainly found in it many inconsistencies" Quran 4:82

Preserved word for word

Allah promises to protect the Quran (Quran 15:9). Muslims point to how that has played out. It was memorised and written down during the Prophet's ﷺ lifetime, and millions of people have memorised it since. The Arabic text recited in London, Cairo and Jakarta is the same. See Was the Quran changed over time?

The man who brought it

Muhammad ﷺ could not read or write, and the Quran notes that before revelation he did not write any book (Quran 29:48). His people had known him for decades as honest and trustworthy. Believers see it as unlikely that an unlettered man could produce such a book himself, and equally unlikely that someone known for honesty would lie about God.

What about proof?

Some people are moved by the language, others by the preservation, others by how the Quran answers their deepest questions about life and death. Many also mention scientific points, though that is a debated area. See Does the Quran contain scientific miracles?

The best way to judge is to read it yourself, slowly, with an open mind. Nobody needs to believe on someone else's word.

Key points

Muslims cite its language, consistency, preservation and the Prophet's ﷺ life.
The Quran invites reflection and challenges doubters (Quran 2:23, 4:82).
Its Arabic text is preserved and recited the same way worldwide.
Belief is a personal journey; reading it yourself is the best test.

Tip: Listen to a short surah, such as Surah al-Fatihah or Surah Maryam, in Arabic with an English translation beside you. Hearing the recitation helps many people understand why others find it so moving.