Heresy in Christianity denotes the formal denial or doubt of a core doctrine of the Christian faith as defined by one or more of the Christian churches. The study of heresy requires an understanding of the development of orthodoxy and the role of creeds in the definition of orthodox beliefs, since heresy is always defined in relation to orthodoxy. Orthodoxy has been in the process of self-definition for centuries, defining itself in terms of its faith by clarifying beliefs in opposition to people or doctrines that are perceived as incorrect. Etymology The word heresy comes from haeresis, a Latin transliteration of the Greek word originally meaning choosing, choice, course of action, or in an extended sense a sect or school of thought, which by the first century came to denote warring factions and the party spirit. The word appears in the New Testament, usually translated as sect, and was appropriated by the Church to mean a sect or division that threatened the unity of Christians. Heresy eventually became regarded as a departure from orthodoxy, a sense in which heterodoxy was already in Christian use soon after the year 100. Definition Heresy is used today to denote the formal denial or doubt of a core doctrine of the Christian faith as defined by one or more of the Christian churches. It is distinguished from both apostasy and schism, apostasy being nearly always total abandonment of the Christian faith after it has been freely accepted, and schism being a formal and deliberate breach of Christian unity and an offense against charity without being based essentially on doctrine. Early Christianity (1st century – c. 325 AD) Development of Orthodoxy The development of doctrine, the position of orthodoxy, and the relationship between the early Church and early heretical groups is a matter of academic debate. Walter Bauer, in his Orthodoxy and Heresy in Earliest Christianity (1934/1971), proposed that in earliest Christianity, orthodoxy and heresy did not stand in relation to one another as primary to secondary, but in many regions heresy was the original manifestation of Christianity. Bauer reassessed as a historian the overwhelmingly dominant view that for the period of Christian origins, ecclesiastical doctrine already represented what is primary, while heresies, on the other hand somehow are a deviation from the genuine (Bauer, "Introduction"). Scholars such as Pagels and Ehrman have built on Bauer's original thesis. Drawing upon distinctions between Jewish Christians, Gentile