[1][3] Dursun was frequently threatened by Islamic fundamentalists, and on 4 September 1990 was assassinated outside his home in Istanbul, after which his books sold tens of thousands of copies in Turkey.

Using his position, he initiated a number of projects for the development of the area and its imams:[6] Dursun gained a lot of followers and enemies at Sivas and was threatened on numerous occasions.

[6] In an interview with Şule Perinçek, Dursun recounted one of the first instances, where he began doubting the existence of God.

[6]Dursun discovered what he called "Muhammad's passings on" when he began learning about the holy books that existed prior to the Quran.

[6] After coming to negative conclusions about religion, Dursun became "angry" that Mohammed took away valuable years of childhood and youth.

[6] Due to a number of friends he made as a thinking mufti, he was able to get a foot in at the Turkish Radio and Television Corporation, (TRT), working firstly in basic administrative positions before taking and passing an exam to become involved in programme production.

[6] In 1987, Dursun was introduced to Doğu Perinçek, a self-proclaimed socialist politician with heavy nationalist undertones, who was the editor of the magazine 2000'e Doğru (Towards 2000).

He wrote countless books in the 1980s, including a Turkish translation of Ibn Khaldun's Muqaddimah, collating his vast knowledge of Islam and languages of the Middle East, opening the religion to internal criticism through the mass media, perhaps for the first time in the religion's history.

[6] On 4 September 1990,[1][7] shortly after leaving his home[1] in the Asian part of Istanbul on his way to work,[7] Dursun was assassinated by two gunmen.

[8] In 1996, İrfan Çağırıcı was arrested, suspected of being involved in the assassination of Dursun, as well as the killing of journalist Çetin Emeç in March 1990 and the kidnapping of Akbar Ghorbani (the People's Mujahedin of Iran's representative in Ankara).