Adnan Oktar (Harun Yahya)
God reveals in the Qur'an that Muslims must believe in our Prophet Muhammed (may God bless him and grant him peace) and in all the prophets sent before him and in everything sent down to those prophets. In verse 4 of Surat al-Baqara, our Lord says that Muslims are "those who believe in what has been sent down to you and what was sent down before you..."
As revealed in the Qur'an, the Gospel, Torah, Psalms and the pages of Abraham are books sent down to prophets who lived in the past. Some of these books have disappeared, while others have been altered or distorted. But they nevertheless contain a great many correct pronouncements belonging to the true faith. Muslims analyze these according to the Qur'an and the Sunna [teachings of the Prophet Muhammad (may God bless him and grant him peace)] and decide that they are correct statements compatible with verses and the hadith.