Proto-orthodox Christianity is a term, coined by New Testament scholar Bart D. Ehrman, used to describe the Early Christian movement which was the precursor of Christian orthodoxy. Ehrman argues that this group, which became prominent by the end of the 3rd century, "stifled its opposition, it claimed that its views had always been the majority position and that its rivals were, and always had been, ‘heretics,’ who willfully ‘chose’ to reject the ‘true belief’." Critics such as Larry W. Hurtado argue the traditional view that proto-orthodox Christianity arose directly from the immediate followers of Jesus.
In order to form a New Testament canon of uniquely Christian works, proto-orthodox Christians went through a process that was complete in the West by the beginning of the 5th century. Athanasius, bishop of Alexandria, Egypt, in his Easter letter of 367, listed the same twenty-seven New Testament books as found in the Canon of Trent. The first council that accepted the present canon of the New Testament may have been the Synod of Hippo Regius in North Africa (AD 393); the acts of this council, however, are lost. A brief summary of the acts was read at and accepted by the Councils of Carthage in 397 and 419.
To Ehrman, "Proto-orthodox Christians argued that Jesus Christ was both divine and human, that he was one being instead of two, and that he had taught his disciples the truth."  This view that he is "a unity of both divine and human" (the Hypostatic union) is opposed to Adoptionism (only human), Docetism (only divine), and Dyophysitism (two natures).
For Ehrman, in the canonical gospels, Jesus is characterized as a Jewish faith healer who ministered to the most despised people of the local culture. Miracle working was not uncommon during an era “in the ancient world [where] most people believed in miracles, or at least in their possibility.” Although most faith healers profited from their miracles, Jesus wandered about healing the poor and disreputable.
The traditional Christian view is that orthodoxy emerged to codify and defend the traditions inherited from the Apostles themselves. Hurtado argues that Ehrman's "proto-orthodox" Christianity was linked to, and reliant upon, the earliest Christian expression of the faith in the Apostolic Age:
...to a remarkable extent early-second-century protoorthodox devotion to Jesus represents a concern to preserve, respect, promote, and develop what were by then becoming traditional expressions of belief and reverence, and that had originated in earlier years of the Christian movement. That is, proto-orthodox faith tended to affirm and develop devotional and confessional traditions... Arland Hultgren has shown that the roots of this appreciation of traditions of faith actually go back deeply and widely into first-century Christianity.
- Ante-Nicene Fathers
- Diversity in early Christian theology
- First seven Ecumenical Councils
- Historical Jesus
- Orthodox Christianity
- State church of the Roman Empire
- Bart D. EhrmanThe New Testament: A Historical Introduction, p. 7.
- "Canon of the New Testament". Catholic Encyclopedia. New York: Robert Appleton Company. 1913.: "So at the close of the first decade of the fifth century the entire Western Church was in possession of the full Canon of the New Testament. In the East, where, with the exception of the Edessene Syrian Church, approximate completeness had long obtained without the aid of formal enactments, opinions were still somewhat divided on the Apocalypse. But for the Catholic Church as a whole the content of the New Testament was definitely fixed, and the discussion closed."
- McDonald & Sanders' The Canon Debate, Appendix D-2, note 19: "Revelation was added later in 419 at the subsequent synod of Carthage."
- Bart D. Ehrman The New Testament: A Historical Introduction, p. 7.
- E. P. Sanders The Historical Figure of Jesus
- Larry W. Hurtado, Lord Jesus Christ: Devotion to Jesus in Earliest Christianity., William B Eerdmans Publishing, 2005, p.495