What is heresy? This has proven to be a remarkably difficult question to answer. Along the way, we’ve tested a number of possible solutions:

• The Conciliar Answer: Heresy is whatever one of the seven ecumenical councils said it was.
• The Power Struggle: Heresy is just the position of the “loser” in the debate.
• The “Other” Answer: Heresy is an exclusionary process used to establish the identity of some group.
• Sugar in My Coffee: Heresy is whatever corrupts the essence of Christianity.
• Just Shut Up!: Heresy is rejecting church authority.

And, with each, we saw that there were good reasons for rejecting it as an adequate definition of heresy. So, we still don’t seem to have a particularly good answer to our question.

But, instead of trying to take each as an adequate definition in its own right, what if we took the strengths of each and used them all to build a definition of heresy? What might that look like?

1. Heresy requires an exercise of authority.

Both the Conciliar Answer and the Just Shut Up! approach recognize that some kind of authority is inherent in the idea of heresy. After all, someone needs to make the final decision as to what does and doesn’t qualify as heresy. I’ve already explained why I don’t think authority alone suffices to define heresy, but that doesn’t mean authority isn’t part of the equation.

Now, as a good evangelical Protestant, the question always arises: Whose authority? Alister McGrath suggests that heresy requires the authority of ecumenical gathering (Heresy: A History of Defending Truth). In other words, unless Christians everywhere can agree that something is heretical, we shouldn’t use the term. And consequently, he pretty much limits heresy to the first few centuries of the church. But, he fails to mention that even these earliest councils weren’t as “ecumenical” as we think (a few hundred bishops from mostly Greek-speaking churches hardly qualifies as fully representative of the whole church, regardless of how good their conclusions might have been). And, as I’ve argued before, such an approach necessarily robs us of the ability to deal with any possible heresies that arose after this time.

But, if I can’t appeal to ecumenical gatherings or to an official magisterium, where can I turn? I’m comfortable saying that the authority in view here is the authority of whatever ecclesial body you are a part. I realize that this makes “heresy” a bit messy in that something might qualify as heresy for one group of Christians and not another. But, complex issues like heresy and orthodoxy are rarely simple.

What this primarily means is that my view would reject the idea that heresy can be a purely individualistic affair. I can’t determine by myself what “heresy” is, though I can certainly offer opinions as to what some group should declare to be heresy.

2. Heresy necessarily involves power and exclusion.

If heresy involves the authority to identify something as “off limits,” then it necessarily involves both power and exclusion. I don’t mean the power to physically coerce someone into believing what you think is correct, though power has often been used that way in the history of heresy. I’m simply talking about the fact that any authoritative declaration that something qualifies as heretical is inherently an exercise of power. And, when that power gets exercised, it necessarily identifies some group as an “other” who lies beyond the pale of orthodoxy.

And, there’s nothing necessarily wrong with either of these. In and of themselves, neither power nor exclusion are bad. Church leaders sometimes need to use both for the benefit of the body (e.g. excluding a dangerous person from a children’s ministry).

But, I think it’s important to be clear that when we use the label “heresy” we are wielding the power to exclude. My fear is that if we don’t make this explicit, we’ll wield the power without being aware that we’re doing so. And, that is exceptionally dangerous. It’s like giving someone a box and not bothering to mention that there’s dynamite inside. We can’t wield carefully what we don’t know that we’re wielding.

So, we must always be mindful that calling something “heresy” is necessarily an exercise of power that should be done with care, prayer, and great hesitation.

3. Heresy undermines the Gospel.

As I mentioned in Sugar in My Coffee, the idea that heresy at its core is something that undermines the essence of Christianity is the approach I resonate with the most. And this for two reasons. (1) Heresy is about essential, rather than peripheral, matters. Granted, it’s not always easy to tell the difference. But, it’s still important to emphasize this throughout. And, (2) heresy comes from within. We make a mistake when we see heresy as something that attacks Christianity from without. Instead, we must realize that heresy is always something that arises from within the body and must be dealt with as such.

But, although I like this approach, I think it needs to be strengthened in several important ways. First, it needs to make the appeal to authority/power more explicit as I’ve done above. Rather than simply presume that heresy is self-evident, we need to recognize that sifting heresy from orthodoxy is a difficult process that will often require a final decision to be made by those entrusted with the authority to do so. Second, we need to realize that the “essence” of Christianity is more than a set of beliefs. (It’s not less than that, but it is more.) So, I wonder if it would be worth exploring whether “heresy” is a concept that could be applied to lifestyles as well as theologies. If a group’s lifestyle runs contrary to the essence of Christianity, wouldn’t it be worth calling it heresy even if that group maintained the outward form of right belief? In other words, can we have a heretical counterpart to orthopraxy as well as orthodoxy? And, finally, I think the idea of Christianity’s “essence” is far too vague. I’d rather say that heresy is something that undermines the Gospel itself. I realize that gets us into a discussion of what the Gospel is. But, I’d rather have a productive discussion about the nature of the Gospel than spin our wheels chasing some abstract “essence.”

So, What Is Heresy?

This is far from final, but here is what I would propose at this point as a definition of heresy: