What is the religion classification of muslim scholars? How did muslim scholars classify religion?
Religions are generally divided into three:
1) Real religions: These are the religions revealed to people by Allah through His prophets. These are called “divine religions”, “true religions” or “heavenly religions”.
Divine religions inculcated the belief in the Oneness of Allah (tawḥīd), which started with Adam (as) and ended with Muhammad (saw). Believing in God, angels and the Last Day is a common feature of all monotheistic religions. It is natural that the religion of divine origin, which was revealed by a prophet, a book, or some pages, should be in accordance with the necessities of its own time and prophet for every nation. There have been differences between religions only in terms of some acts of worship, human relations, and transactions. This is closely related to the development of culture and civilization, population growth, and the increase in needs. Only when the divine message that had been sent to human beings until the time of Jesus was altered and its originals were lost, did Allah Almighty send Islam, the last and most perfect religion, to humanity through Muhammad (saw).
Today Islam is the only true religion on earth. The following is stated in the Qur’an: “The Religion before Allah is Islam (submission to His Will): Nor did the People of the Book dissent therefrom except through envy of each other, after knowledge had come to them. But if any deny the Signs of Allah, Allah is swift in calling to account.” “It is He Who has sent His Messenger with guidance and the Religion of Truth, to proclaim it over all religion, even though the Pagans may detest (it).” “If anyone desires a religion other than Islam (submission to Allah), never will it be accepted of him; and in the Hereafter He will be in the ranks of those who have lost (All spiritual good).”
2) Religions whose original form has been altered: While these are true religions in terms of their origins, as stated above, they have subsequently been corrupted and the originals of the holy books on which they are based have disappeared. They are religions like Judaism and Christianity.
Although the Torah, Psalms, and Bible were texts celebrated as holy books in their own time, they have undergone changes through the historical process. “The Bible”, which includes the Torah, Psalms, and the Gospels, which are in the hands of today’s people of the book, as Muhammed Hamidullah said, is composed of books by authors who lived in different periods and had different literary styles. These include historical books, religious and political speeches, pure prayers, books of wisdom, stories of the prophets, philosophical dialogues, and texts of law. A text with religious elements that were written in later periods was signed by a wise person “Solomon”, an inspired historian “Moses” and a prophetic person “Isaiah”. Jesus’ style was slightly different. He did not write down anything but gave sermons and talks throughout his mission. This is why the text of the New Testament that was written later on is a biography of Jesus. This biography contains information on what Jesus said or did and information that the Gospel writer learned from other sources. Accordingly, the Bible is similar neither to the Qur’an nor to the hadiths. It can be said that they are similar to the Sirah books, some of which belong to the Companions’ period and some of which belong to even later periods. The Gospels are therefore similar to the biographies of Muhammad. There are many copies of the Gospels -about sixty-, of which the Gospels of Matthew, Mark, Luke, and John were generally accepted by the Christian denominations. The rest have been declared as fabrications, of which the Gospel of Barnabas is of particular interest.
The belief in the deity of these religions also shows a departure from the creed of tawḥīd. The Torah, which has been added and subtracted to a large extent by its own clergy, has given Judaism a national character today, and the belief that Allah (Yahweh), the owner of the earth and sky, is only the God of the sons of Israel, and that other nations have been created to be subjects of them, is inculcated. It is possible to come across such indoctrinations in many parts of the Torah that we possess today. In Christianity, accepting Jesus as God and the Son of God or as one of the three gods (trinity) is one of the points that lead them to polytheism and unbelief.
3) False religions: These are religions that have no link with the belief of tawḥīd in terms of their origins. Their source is not revelation, but human. They are things that some societies have made up and introduced under the name of religion. Even though they consist of some provisions in accordance with reason, wisdom, and social benefit, they do not have sacredness because they are not based on Almighty Allah and a prophet sent by Him. Characteristics such as worshiping the moon, the sun, the stars, some animals that they consider sacred, idols that they made with their own hands, or some natural forces are their nature. Religions such as Hinduism, Buddhism, Zoroastrianism, and Shamanism as seen throughout history can be listed among such religions.
 Āl ʿImrān, 3: 19.
 Al-Tawba, 9: 33; al-Fatḥ, 48: 28; al-Saff, 61: 9.
 Āl ʿImrān, 3: 85.
 M. Hamidullah, Aziz Kur’an, Beyan Yayınevi, Istanbul, n.d., p. 22-23.
 The Bible (Torah and the Gospels) Istanbul, 1958, see p.73 and other similar pages; Günay Tümer- Abdurrahman Küçük, Dinler Tarihi, Ankara, 1988, p. 114 ff.
 See al-Mā’ida, 5: 72-73; Tümer-Küçük, ibid, p.142, 148 ff.
 See Tümer-Küçük, ibid, p. 45, 64, 91 ff.