I can only speak for myself but I read the bible - various translations - and the Koran, the Book of Mormon, etc., etc., because I am interested in history, the history of religion and the psychology of the religious. I regard the New Testament as a jigsaw puzzle - a mystery awaiting solution.
//Why would a creationist read The God Delusion?//
I don’t believe many would. I have a scrap of a book on my shelf by Alister McGrath, a theologian and Christian apologist. Entitled ‘’The Dawkins Delusion’, it claims to be a refutation of Richard Dawkins’ work. In actual fact it is no more than a poor attempt at character assassination.
I once entered into an agreement with a religionist here. He was to read ‘The God Delusion’ and my task was to read a book he recommended - ‘Islam and the Destiny of Man’ by Gai Eaton, which still sits on my shelf. I kept my part of the bargain.