According to Bart Ehrman, nearly all scholars who study the early Christian period believe that he did exist and Ehrman observes that mythicist writings are generally of poor quality because they are usually authored by amateurs and non-scholars who have no academic credentials or have never taught at academic institutions. Maurice Casey, theologian and scholar of New Testament and early Christianity, stated that the belief among professors that Jesus existed is generally completely certain. According to Casey, the view that Jesus did not exist is "the view of extremists", "demonstrably false" and "professional scholars generally regard it as having been settled in serious scholarship long ago".