Misinformation abounds about the origins of Christianity. Some individuals assert that by the time of the Council of Nicaea under Constantine in AD 325, there were upwards of 80 (disagreeing) gospels which competed for the traditional four slots (this many-gospels account is quite a desperate move, having no positive support along with a sizable case against it). Most who hold to this view contend is that the Church rather arbitrarily selected Matthew, Mark, Luke, and John out of this pool of contenders for political reasons. Other contemporary writers assert that after a supposed period of conflict and division, alternative “Christianities,” such as the various varieties of gnosticism, were unfairly snuffed out by the growing power of the church of Rome. Perhaps the most influential of these theories is the Bauer thesis, which argues that Christianity began in diversity and only later moved into unified orthodoxy. Unfortunately for the Bauer thesis, the exact opposite is true, as Andreas Kostenberger and Michael Kruger argue in the book, The Heresy of Orthodoxy (2010). It is increasingly common to believe that modern Christianity survived because it gained political power over other, equally compelling alternatives.
Recently in a used bookstore, I came across a strikingly and distressingly large section titled, “Alternative Church History,” which was filled with works on the gnostic “gospels” and gnosticism itself. Unfortunately for those who wish to revise history by exalting early heresies to a level of popularity far beyond what the historical record supports, the facts of history are not up for grabs. The early church did not hide these heresies from public view, or try to dispose of the evidence of “alternative Christianities,” but openly and confidently exposed and refuted their errors. In the early church, gnosticism was never considered to be a separate branch of Christianity, but was recognized as something else entirely. Thus, gnostic texts were never an option for inclusion into the canon. These historical realities are being obscured and must be reestablished. Early writers such as Irenaeus (active around the late second century, long before the existence of Constantine and the Council of Nicaea) are of great help to us in dispelling falsehoods and rumors caused by the irresponsible pens of certain contemporary writers.
Perhaps most important is [Irenaeus’] treatment of Scripture, which was not yet in canonical form throughout Christian communities. Irenaeus successfully appeals to a notion of catholicity, that most churches everywhere in the late second century see a certain collection of writings to be Scripture. He helps to prove that churches were not in disarray, uncertain of authoritative texts of the faith, but generally united in agreeing on most books and especially not agreeing on an entirely different and threatening genre of books: gnostic writings. Thus the voice of Irenaeus still disallows even contemporary gnostic fans like Elaine Pagels, critical historians like Bart Ehrman and popular authors like Dan Brown. He is the first to refer to a four-Gospel canon, to defend most thoroughly the apostolic authority of the Gospel writers and Paul, and among the earliest defenders of the book of Revelation while still disputed among some churches. — W. Brian Shelton, “Irenaeus,” in Shapers of Christian Orthodoxy, ed. Bradley G. Green, pp. 51-53