Alister McGrath overviewed the epic, centuries-long battle between good and bad theology in Heresy: A History of Defending the Truth. Here are five ideas about heresy that, according to McGrath, are either myths or misconceptions.
Myth One: Heresy arose from boredom with orthodox doctrine and an appetite for something new
Most of the classic heresies arose during the first four hundred years of church history, what is called the patristic period. During that time, there was nothing newer than Christianity. In those early years, heresies were often a reaction against the newness of new faith, as McGrath explains:
Far from being “innovative” or “radical,” many heresies were actually rather conservative, attempting to hold on to traditional ideas that were being undermined by the more radical ideas developed by early Christianity. The ideas of Gnosticism, for example, seem rather dull and plodding compared with the transformative Christian notion of the Incarnation.
In the case of Gnosticism, McGrath elaborates, with the help of N. T. Wright. When Christianity was new, Gnosticism was old. Now, Gnosticism has been “rediscoverd,” and in some cultures, orthodox Christianity suffers from what McGrath calls “familiarity fatigue”:
The British New Testament scholar N. T. Wright dismisses the widespread belief that Gnosticism was innovative, providing a surge of creative intellectual energy that threatened to sweep away traditional ideas. If anything, Wright argues, it is the Gnostics who are better seen as the cultural conservatives, echoing many of the themes of the mystery religions of the age. In contrast, the orthodox Christians “were breaking new ground,” and encountering opposition for doing so. Where some suggest that the Gnostic Gospels represent radical alternatives to the “conservative” canonical Gospels, Wright argues that quite the opposite is true. It is the message of the New Testament that is truly radical. Yet centuries of cultural familiarity with Christianity, together with the relative novelty of a rediscovered Gnosticism, have created a somewhat different cultural perception. Religious orthodoxy has become the victim of a familiarity fatigue, which creates a yearning for novelty.
Myth Two: The earlier the doctrine, the more likely it is to be orthodox
The New Testament had just barely been written when people were getting it wrong. When I read the New Testament, I am not surprised that it took the church several hundred years to learn how not to be heretics.
Nevertheless, since the second century, the older doctrines were considered more likely to be correct:
It is easy to understand why many might believe that early patterns of faith are the most authentic. Yet recognizable forms of views that the church later declared to be heretical—such as Ebionitism and Docetism—can be identified within Christian communities as early as the late first century. Although many early Christian writers, such as Tertullian, held that the antiquity of a theological view was a reliable guide to its orthodoxy, this is simply not correct. Mistakes were made, right from the beginning, that later generations had to correct.
Myth Three: Orthodoxy is fixed and unchanging
This is related to the previous myth. If orthodoxy took some time to work out, there is no guarantee that it has been worked out perfectly, or that it will never need adjustment.
Orthodoxy is just our human expression of the truth. If nothing else, language changes, and older teachings get misunderstood.
McGrath puts some of the responsibility for the myth of fixed orthodoxy on the third century writer Tertullian:
For Tertullian, heresy was about innovation, change, or modification of the pristine doctrinal truth of antiquity. Yet if it is accepted that orthodox doctrine develops over time, Tertullian’s method of identifying and accounting for heresy is left stranded.
Twentieth century theologian H. E. W. Turner labeled the kind of view Tertullian held, calling it archaism:
In his influential study of the nature of heresy, H. E. W. Turner identified a number of pressures that led to heretical outcomes. One of the most intriguing is what Turner terms archaism—a refusal to accept that development in Christian thinking is necessary. Turner’s point is significant, as it draws attention to the fact that the church gradually found the repetition of earlier formulas to be inadequate as a means of ensuring continuity, except at the purely formal level, with the apostolic church. An instinct to preserve tradition by reiteration gradually gave way to the realization that the church must continue its history by restatement and interpretation of those traditions.
Other church fathers disagreed with Tertullian. Athanasius was one of them:
The patristic quest for orthodoxy did not proceed on the assumption that this best account had yet been found, even though it assumed that some reasonable approximations had been developed. In a certain sense, writers such as Athanasius of Alexandria held that orthodoxy had yet to be discovered.
Undiscovered orthodoxy does not mean new truth. Neither is it an addition to the “faith that was once for all delivered to the saints” (Jude 3). In the word of nineteenth century theologian John Henry Newman, it is a matter of “further insights” rather than “new truths.”
Myth Four: Heretics had evil intentions
Most of the early heresies were begun by men who sincerely thought they were helping the church. As McGrath points out, it seemed at first that they were helping to advance true Christianity. Only in time was their error made clear:
The central defining paradox of heresy is that it is not unbelief; it is rather a vulnerable and fragile form of Christianity that proves incapable of sustaining itself in the long term.
McGrath provides the following definition of heresy, rooting it in failure, not malice:
A heresy is a failed attempt at orthodoxy, whose fault lies not in its willingness to explore possibilities or press conceptual boundaries, but in its unwillingness to accept that it has in fact failed.
The myth of the sinister heretic was promulgated by the very men who were instrumental in defeating these heresies. Their strategy was this: link the bad teaching with a specific man, then demonize that man so others will not want to be associated with him.
Tertullian again gets some of the blame for this myth:
There is evidence of an emerging “official” narrative of the origins of heresy, locating its genesis in personal rivalry, ambition, and dishonesty in the late second and early third centuries. Tertullian, who played a significant role in the formulation of this alternative account, tells us that the Roman church threw out Marcion on account of his heretical views. Tertullian portrays the origins of Marcion’s heresy as lying in thwarted personal ambitions…
This was Tertullian’s approach to answering other heretics as well:
Tertullian regularly portrays heretics such as Valentinus as frustrated and ambitious, and ascribes their views to resentment at their failure to achieve the recognition of high ecclesiastical office.
Tertullian was not the only heresy fighter who used this approach. Irenaeus did it too:
The impression created by some patristic writers is that heretics were outsiders who sought to subvert or destroy the church. The origins of this inaccurate stereotype of heresy are now reasonably well understood. In recent years, increased attention has been paid to the strategies devised by Irenaeus of Lyons to exclude certain individuals and teachings from the church. A new “heresiology” emerged in the late second century as a way of portraying heresy that attempted to mask the fact that heresy had its origins within the church, occasionally even remaining present within it. Making use of established forms of “philosophical invective,” Irenaeus and others argued that heretics were impostors, wolves in sheep’s clothing, who pretended to be members of the church yet were ultimately bent on its destruction.
Myth Five: Orthodoxy represents the opinion of the powerful
“Heresy is the orthodoxy of history’s losers” is how McGrath summed up this myth.
This myth usually begins with the Emperor Constantine, who legalized Christianity in 313 AD. However, the church dealt well with heresy for the three centuries before this. And they did so without any kind of earthly power:
The early church was socially fragmented, disconnected from influence and power within the imperial structures. There was no question of some centralized church authority “imposing” its views on other congregations, as the church was denied access to political or military power. No mechanism for preventing diversification or enforcing orthodoxy existed.
At the time of the Nicene Council (325 AD), Constantine wanted the church to be agreed on doctrine, and he wanted this for the reason of political expediency. But if he had simply imposed his own view on the church, it would have been the Arian heresy:
The evidence suggests that Constantine ultimately could have worked with either the position espoused by Athanasius or that espoused by Arius, yet he had a preference for the latter. Constantine was quite clear about his role; it was the church itself that had to decide which was right and bring the dispute to an end. His role was to bring about an unequivocal conclusion.
This idea of politically enforced orthodoxy was put to the test after Constantine died. Constantine’s son, Constantius, reversed the decision of the Nicene Council. He declared that the Arian heresy was the official doctrine. The church, however, fought hard against this. Arianism was backed by imperial might, but it was still not theologically right. And it still lost the battle:
The political decision that Arianism was orthodox and its rivals heretical provoked detailed intellectual examination of the credentials of the theological options available to the church. Writers such as Basil of Caesarea and Gregory of Nazianzus offered a theological analysis that led to a significant tension emerging between the intellectual merits of a theology and its political expediency. Arianism might have been imposed upon the church by an act of imperial authority; it was, however, becoming clear that it was not the best intellectual option. In the end, political influence proved inadequate to sustain a deficient vision of the Christian faith. While Arianism would continue to exercise influence in peripheral regions of the church for some time, its centers of influence had been won over again to the Nicene vision of the faith.
As the church grew strong politically, it did indeed use its power to crush dissent. And it did label dissent as heresy. But this was an inaccurate label, and probably helped this myth to take hold. It created confusion about what the word heresy means:
It is clear that medieval movements such as the Hussites, Waldensians, and Lollards were seen as threats to the church not so much on account of their ideas as on account of their popular appeal. They had the potential to become alternative centers of power and influence, bypassing or challenging the centralized structures of the church. It has been realized for some time that it is not appropriate to use the term “heresy” to refer to such movements.
Identify heresies, not heretics. Calling someone a heretic is not likely to change their mind. Instead, acknowledge their good intentions and show them the logical outcome of what they are teaching.
Fight against familiarity fatigue. True Christianity is still the most intellectually exciting thing on the face of the earth. If you find it boring, the problem lies with you.
Plunder the silver of Egypt, but leave the idols behind. The early church fathers debated how much they could borrow from their surrounding culture. They completely rejected Gnosticism. They differed, however, in their approach to Greek philosophy. Augustine used the analogy of the Israelites leaving Egypt. They took the wealth of Egypt with them. This represents the good ideas of the world. Of course, they also took the idols, which was a big mistake.
 McGrath, Alister. Heresy: A History of Defending the Truth (p. 218). HarperOne. Kindle Edition.
 N. T. Wright, Judas and the Gospel of Jesus: Have We Missed the Truth About Christianity? (Grand Rapids, MI: Baker Books, 2006
 McGrath, pp. 10-11
 McGrath, p. 28
 McGrath, p. 71
 H. E. W. Turner, The Pattern of Christian Truth: A Study in the Relations Between Orthodoxy and Heresy in the Early Church (London: Mowbray, 1954), 132-41
 McGrath, p. 66
 McGrath, p. 27
 McGrath, pp. 67-68
 McGrath, p. 83
 McGrath, p. 31
 McGrath, p. 63
 McGrath, p. 64
 McGrath, pp. 58-60
 McGrath, p. 197
 McGrath, p. 55
 McGrath, p. 148
 McGrath, pp. 204-205
 McGrath, p. 103