In ecclesiology, the Christian Church is what different Christian denominations conceive of as being the true body of Christians or the original institution established by Jesus Christ. "Christian Church" has also been used in academia as a synonym for Christianity, despite the fact that it is composed of multiple churches or denominations, many of which hold a doctrinal claim of being the one true church to the exclusion of the others.
For many Protestant Christians, the Christian Church has two components: the church visible, institutions in which "the Word of God purely preached and listened to, and the sacraments administered according to Christ's institution", as well as the church invisible—all "who are truly saved" (with these beings members of the visible church). In this understanding of the invisible church, "Christian Church" (or catholic Church) does not refer to a particular Christian denomination, but includes all individuals who have been saved. This is in contrast to the one true church applied to a specific concrete Christian institution, a Christian ecclesiological position maintained by the Catholic Church, the Lutheran Churches, the Eastern Orthodox Church, the Oriental Orthodox churches, Assyrian Church of the East, and the Ancient Church of the East. While holding this view, the Lutheran Churches teach that "there are indeed true Christians in other churches" as "other denominations also preach the Word of God, though mixed with error". The branch theory, which is maintained by some Anglicans, holds that those Churches that have preserved apostolic succession are part of the true Church, though the majority of Anglicanism has historically "followed the major continental Reformers in their doctrine of the true church, identifiable by the authentic ministry of word and sacrament, in their rejection of the jurisdiction of the pope, and in their alliance with the civil authority ('the magistrate')".
