Short answer
Converts often mention the clear belief in one God, the Quran, the daily prayer, the honour Islam gives to Jesus and the earlier prophets, and a sense of purpose and community. Muslims believe the deeper reason is guidance from Allah, who created every person with a natural inclination toward Him, the fitrah.
Once a person believes that there is no god but Allah and that Muhammad ﷺ is His messenger, accepting Islam is fard (obligatory) on them and should not be delayed. Islam may never be forced on anyone. Saying the shahada with sincere belief is enough to enter Islam.
The four schools agree on this.
Explanation
The Quran says Allah created people upon the fitrah, a natural disposition to know and worship Him, and the Prophet ﷺ said every child is born upon it. Many new Muslims describe their conversion as coming home to something they already felt, which is why some call themselves reverts.
Reasons converts often give:
- One God, directly: no Trinity and no intermediary. You pray to Allah yourself, in any language, at any time.
- The Quran: many read a translation and find it speaks to them, as the Quran describes Christians who wept when they heard it.
- Prayer and structure: five daily prayers, Ramadan and clear guidance on daily life.
- Jesus and Mary honoured: Christians are often surprised that the Quran loves Jesus and has a surah named after Mary.
- Purpose: clear answers on why we exist and what comes after death. See purpose of life in Islam.
- People: the character of a Muslim friend, neighbour or colleague.
Muslims also believe in great spiritual benefits: the sins before Islam are wiped away, and hearts find rest in the remembrance of Allah. See are past sins forgiven?
Still, the Quran reminds us that guidance belongs to Allah: no person can make another believe. A conversion should come from real conviction, not pressure or only for marriage. If you are thinking about it, take your time, read, ask questions, and when you are ready see how to convert to Islam.
The evidence
Quran, Surah Ar-Room 30:30
فَأَقِمْ وَجْهَكَ لِلدِّينِ حَنِيفًۭا ۚ فِطْرَتَ ٱللَّهِ ٱلَّتِى فَطَرَ ٱلنَّاسَ عَلَيْهَا ۚ لَا تَبْدِيلَ لِخَلْقِ ٱللَّهِ ۚ ذَٰلِكَ ٱلدِّينُ ٱلْقَيِّمُ وَلَٰكِنَّ أَكْثَرَ ٱلنَّاسِ لَا يَعْلَمُونَ ﴿٣٠﴾
So direct your face toward the religion, inclining to truth. [Adhere to] the fitrah of Allah upon which He has created [all] people. No change should there be in the creation of Allah. That is the correct religion, but most of the people do not know.
Every person is created with a natural inclination toward the one God.
Quran, Surah Ar-Ra'd 13:28
ٱلَّذِينَ ءَامَنُوا۟ وَتَطْمَئِنُّ قُلُوبُهُم بِذِكْرِ ٱللَّهِ ۗ أَلَا بِذِكْرِ ٱللَّهِ تَطْمَئِنُّ ٱلْقُلُوبُ ﴿٢٨﴾
Those who have believed and whose hearts are assured by the remembrance of Allah. Unquestionably, by the remembrance of Allah hearts are assured."
Many converts describe the peace of heart that faith and dhikr bring.
Quran, Surah Al-Qasas 28:56
إِنَّكَ لَا تَهْدِى مَنْ أَحْبَبْتَ وَلَٰكِنَّ ٱللَّهَ يَهْدِى مَن يَشَآءُ ۚ وَهُوَ أَعْلَمُ بِٱلْمُهْتَدِينَ ﴿٥٦﴾
Indeed, [O Muhammad], you do not guide whom you like, but Allah guides whom He wills. And He is most knowing of the [rightly] guided.
Guidance to Islam is a gift from Allah, not something one person forces on another.
Sahih al-Bukhari 1358
Sahih... ما من مولود إلا يولد على الفطرة ...
"Every child is born upon the fitrah, the natural state."
The basis for seeing conversion as a return to one's natural faith.
Where the ruling is recorded
- al-Fiqh al-Akbar, the section on the definition of iman. Faith is belief in the heart affirmed by the tongue.
Checked by our team. For a more accurate answer to your own situation, consult a scholar. Quran translation by Sahih International. Hadith Arabic from the standard editions of the six books and the Muwatta, with gradings as recorded there; the English is our own rendering. Spotted a mistake? Tell us.