Material heresy is an idea that contradicts a truth which must be believed with divine and catholic faith. Formal heresy is the sin of the person who adheres to material heresy. Formal heresy is a knowing and deliberate choice to adhere to an heretical idea. So it would seem as if heresy is just a particular wrong idea, and if you adhere to that wrong idea, knowingly and deliberately, you are a heretic. If you next renounce that wrong idea, then you are not a heretic. Well, all this is correct.
However, in the case of the big historical heresies, a much different situation prevails. Yes, it is still true that certain false ideas are material heresy, and those who adhere to material heresy, knowingly and deliberately, commit formal heresy. But the practical situation is much more complex. The heresy is not one point of alleged doctrine, but a way of looking at Christianity. The heresy presents a different version of Christianity, since all aspects of the Faith are affected by the particular heretical idea. The point of doctrine in dispute has an effect on the other doctrines. And so the persons who adhere to the heresy are not so much adhering to one error, but to an interconnected set of ideas, which constitute a different version of the Faith. They are not theologians who have reached a different conclusion on a point of faith or morals. They are Christians who see the faith that they are living in a different light, a false light.
The typical historical heresy would be taught by one particular heresiarch, one lead teacher of the heretical group. Essentially, such a person is taking a role similar to that of the Pope, figuratively speaking; I’m not referring to actual antipopes. If a person proposes that the entire Faith should be reconsidered in the light of his particular teaching, he is taking a perverse papal-type role. The Pope defends the deposit of faith. The heresiarch proposes a new version of the faith.
And then, historically, there would be many other lesser teachers also spreading the same version of the faith. The main leader might be a person with attractive attributes: eloquent, charming, humorous, clever, dynamic, intelligent, etc. He might be a person who believes what he teaches passionately and sincerely. When Christians listen to him teach, they see all the good qualities in his person, and they see his love for Christianity. They see a version of the Christian faith which is attractive to them.
When a Christian adopts the heresy, he or she joins a group of fellow Christians, who are generally good people, and who are enthusiastic about this new way of understanding Christianity. There are many good persons in that group, and joining feels good. There is a sense of community and purpose. There is an agreement that their leaders have many good qualities. And the heretical group as a whole reinforces its errors by this community, by the interactions of the members of the group with one another, and by having many different teachers presenting various similar explanations.
And this makes it difficult for a Christian who falls into a heresy to realize that, at the core of all these good people and good qualities, is an idea that is offensive to God, who is Truth, an idea offensive to Jesus, because it is a falsehood attributed to Him.
Now, why don’t all these good persons, with many good qualities, realize that their understanding of the Christian faith contains this error, this heresy? First of all, any major heretical error will always have an effect on other doctrines, distorting them to fit the main error. The result is a set of errors, not only one point of disagreement. So if you try to convince a heretic to give up his heresy, he can’t see the forest for the trees. He can’t see that he is surrounded by a complex interconnected web of errors. If it were an isolated error, the other teachings of the faith could be used to refute that error. But when the heresy reaches to the extent of distorting the other truths, one after another, they are not understood correctly, so they don’t combine to refute the main heresy.
Another problem is that the heretical follower can’t understand how a teacher with many good qualities, who perhaps (to some extent) helps his followers to understand the Christian faith in ways that are real and true, could have erred so gravely. They trust the leader because they admire his good qualities, and because they have learned much from him (or they mistakenly think they have learned much).
And then, as the heresy succeeds in convincing many persons, the follower sees persons of good reputation, of good scholarship, who perhaps hold reputable positions in the Church or in Catholic schools and organizations, also adhering to the error. And this makes it even more difficult to realize that this particular view of the Faith is gravely erroneous. How could so many scholarly and holy persons fall into grave error? It seems, from a human point of view, that they could not.
Sometimes the heresy is linked to a particular culture, society, language, or a certain set of human behaviors. For example, the East-West schism (which certainly includes a number of heresies) was based in part on the differences between the two cultures. This makes it easier for someone to fall into a heresy, if it is based in part on the aspects of culture and society which an individual shares with the other followers of the heresy. For example, when the Anglican Church was formed, in a schism with the Roman Catholic Church, it was difficult for persons who identify as English citizens, as members of the culture and politics of that nation, to decline to join the Church formed around that nation and its monarch.
Another aspect of heresy that attracts followers is when the heresy addresses problems in the Christian faith which are otherwise difficult to explain. The heresy offers an easier answer than that of true doctrine. Calvinism is a simpler answer to difficult questions on salvation than found in true doctrine. Good theology on salvation is complex and hard to understand. Protestant fundamentalism offers a simpler explanation of who is saved and why. Heresy gives simple answers to complex questions. Heresy solves theological problems in ways that are easy to accept.
Then there are the heresies that justify grave sin. One of the more difficult to accept aspects of Christianity is the moral code, that differs from sinful secular society. Some heresies make Christianity easier to accept by denying or changing the condemnation of grave sin found in the true Faith. The Nicolaitans were an early group of heretics who believed and practiced utter sexual promiscuity. It was pleasing to many people to hear a version of Christianity which permits sexual excess. This type of heresy formed around the human behavior of sexual acts, making those acts seem moral or even holy by means of heretical teachings. (Who are the Nicolaitans of today?)
Another example is the modern-day heresy, found among many Catholics, which claims that no human act is always wrong. There are various theological schemes used to reach that conclusion. Some say that intrinsically evil acts are always wrong, but they have various ways to redefine any popular intrinsically evil act they wish to approve, so that it seems moral. Others simply deny that any act is inherently wrong. And the reason his heresy is popular is that it allows popular grave sins to seem moral.
So while it is true that material heresy is a particular idea, and formal heresy is the decision to adhere to that idea, the real-world situation is more complex. Today, there are popular heresies making great progress spreading among sincere Catholic Christians. One of the worst is the distorted version of the theology of the body. The Nicolaitans, in the first century AD, attached the name of one of the first deacons, Nicolas, to their errors. But he was never a member of that group, and he never taught the ideas falsely attributed to him.
Similarly, the perverse version of theology of the body falsely attributes many different errors to Pope Saint John Paul II. And, just as I explained above, this heresy is not one error. It is a set of errors which combine to offer a different version of the Catholic faith. These false teachers think that all of Christianity should be seen through the lens of the theology of the body. They think that every important teaching of the faith should be seen as closely related to marital sexual pleasure, even when that pleasure is obtained by means of unnatural sexual acts. They have revised the faith so that everything revolves around the body and sex, and everything is explained in sexual terms.
When I read Christopher West on the theology of the body, marital sex, and how that relates to the Crucifixion, the Eucharist, and everything most sacred in our Faith, literal tears well up in my eyes. And not in a good way.
Please take a look at this list of my books and booklets, and see if any topic interests you.