by Nathan A. Finn, PhD

Heresy is all the rage.

Just take a stroll through the “Religion” section at any mainstream bookstore. You will find innumerable titles promoting Gnostic revisions of Christianity that claim to be more authentic than what you find in most churches, including those of Baptists and other evangelicals. The authors and editors of these books are convinced that traditional Christianity is hopelessly authoritarian and repressive, more the product of political power-plays by nefarious church leaders than the faith once and for all delivered to the saints. Bestselling authors such as Elaine Pagels and Bart Ehrman suggest the way forward is to recover Gnostic versions of Christianity, which they allege are at least as authentic as what we find in the New Testament.

Like many Christian scholars, British theologian Alister McGrath is fascinated by the appeal that Gnosticism and other ancient heresies hold for so many spiritual seekers. His new book Heresy: A History of Defending the Truth (HarperOne, 2009) is an attempt to understand how heresy arose from, conflicted with and even shaped the church from the earliest days of Christian history to the present. He succeeds on all counts.

McGrath defines heresy as “a form of Christian belief that, more by accident than design, ultimately ends up subverting, destabilizing or even destroying the core of Christian faith” (12). He argues that those who want to retrieve ancient heresies for our own day fundamentally misunderstand the history of both heresy and orthodoxy. McGrath argues that movements such as Gnosticism were not more freethinking or liberating than mainstream Christianity, and often were less so (77-78).

McGrath also counters the claim, first suggested by the German scholar Walter Bauer and recently popularized by Dan Brown in his bestselling novel The DaVinci Code, that there was no such thing as “orthodoxy” until the Catholic Church and the Roman Empire conspired to suppress alternative versions of Christianity. McGrath counters that Christians had no political leverage until after the time of Constantine, and by then most of the early heresies had already been identified and rejected. Furthermore, after Christianity became the favored religion, the Empire at times suppressed orthodoxy when heretical ideas were in vogue among the cultural elites (203).

While McGrath offers no quarter to the neo-heretics, he also shows that many traditional Christians also misunderstand the history of heresy and orthodoxy. The earliest heretics were not anti-Christian wolves who infiltrated the sheep pen, despite the efforts of early theologians such as Irenaeus and Tertullian to paint them in this way. Rather, heresies arose from within the church as professing Christians attempted to revise elements of Christianity to make them more palatable. The revisions were deemed to be unacceptable by the majority because of concern that the heresies actually undermined rather than improved the faith (82-84). Simply put, most heretics were well-meaning, but they accommodated Christianity to the culture to such an extent that the Gospel itself was redefined, obscured or even rejected.

One of the most helpful aspects of McGrath’s book is the extended discussion of classical heresies that arose during the first five centuries of church history. Like many contemporary scholars, McGrath argues that there are no new heresies, but rather periodic revivals of these earlier heresies in updated form. Ebionitism was an early Jewish heresy that interpreted Jesus as a spiritually superior man, but nevertheless a mere mortal. Docetism argued the opposite; Jesus appeared to be a man, but was really a divine being. Valentinism, a well-documented form of Gnosticism, emphasized the superiority of the spiritual over the physical and claimed that salvation was available only to a chosen few who had access to secret redemptive knowledge. Marcionism was an anti-Semitic heresy that rejected continuity between the Old and New Covenants and severed Christianity from its Jewish roots. Each of these heresies arose in the first two centuries after the time of Christ.

The three key heresies of the Fourth and Fifth Centuries are perhaps better known than their earlier counterparts. Arianism argued that Jesus is divine in some sense, but he is not co-eternal with the Father. This view raised serious questions about why Christians should worship Jesus if he is not fully God and how He can save us if He is merely an exalted creature. Donatism argued that the church is only as pure as her leaders, which overemphasized the significance of human agents over God’s gracious work through imperfect vessels. Pelagianism was a legalistic heresy that exalted free will and spiritual effort by claiming that humans are able to perfectly obey God’s commands, thus rendering grace unnecessary for salvation. Each of these heresies can be found today under different names, so pastors and other Christian leaders would do well to give McGrath a close reading on this point.

While McGrath’s discussion of heresy is both insightful and helpful, it is not without some weaknesses. At times, McGrath suggests a greater level of diversity in the New Testament than many evangelicals would countenance. While he comes nowhere close to affirming multiple orthodoxies, he does overemphasize post-New Testament doctrinal development. It is debatable whether development is even the best model to describe how beliefs were articulated and transmitted in the early church. I would suggest contextualization, where doctrines do not “develop,” but are rather translated and adapted when introduced into new contexts, is more helpful. This seems especially relevant to the topic of heresy and orthodoxy. Orthodoxy does not change from the New Testament to the Fifth Century, but it is articulated in new ways to counter the threat of new heresies.

On the whole, Alister McGrath has given the church a useful primer on the history and significance of heresy. Heresy is well-researched and engages a wide breadth of scholarship, but is written in such a way that makes it accessible to pastors and other non-specialists. We live in a culture where the ancient heresies are appealing, even if for suspect reasons. Anyone who regularly teaches God’s Word or is interested in reaching especially college-educated postmodern urbanites with the Gospel should avail themselves of McGrath’s fine book.

Nathan A. Finn PhD, is assistant professor of Church History and Baptist Studies at Southeastern Seminary.