Islamic preachers (such as Sheikh Muhammad Metwally Al Shaarawy) began to take prominence as symbols of popular Egyptian culture.[13] Novels, plays, science-fiction, philosophy books singing the praises of Islam, often by converts from secularism. (An example being My Itinerary from Doubt to Belief, an autobiography by a very popular Egyptian writer, Dr. Mustafa Mahmud, who had formerly been a staunch believer in scientific positivism, human engineering, and materialism. Another prominent ex-secularist convert was Khalid Muhammad Khalid.[14]) The revival led to greater attendance in prayer and growth of non-state-controlled neighborhood mosques, but also to at least some conflict with the minority Coptic Christians of Egypt, an example being Islamist castigation of Muslim participation in the all-Egyptian spring holiday Sham el-Nessim.