In the Qur'an, the terms "religion in the sight of Allah", "true religion", "true religion" are used for Islam.
In the Qur'an, belief systems other than Islam are also called religions. Accordingly, Islam is the true religion because its source is divine and it preserves its originality. Religions (Judaism, Christianity) that cannot preserve their originality even though they are based on divine revelation are called "distorted religions" in the sense that they are changed and falsified.
Religions that are not based on divine revelation are "superstitious religions".
In Islamic sources, the word "milel" is used for religions based on revelation, and the word "nihal" is used for religions not based on revelation.
(İlmihal-I, Diyanet İşleri Başkanlığı); (Catechism-I, Presidency of Religious Affairs)