One of my former teachers used to say that we are all allowed one pet heresy. I am not sure that this is generous enough, but his point is good. I believe that we each have beliefs that are wrong. If we knew which ones we would change them so yours is something you are probably going to defend, and so is mine. Some of us also have beliefs that fall outside the orthodox way of thinking in certain areas. (I am going to keep mine a secret for now!)
How does one know if they have crossed that line?
Well, this is quite a question: Are you orthodox or heretical? Let me offer some rules of engagement for dealing with this issue.
In order to be a heretic, you have to fall outside the orthodox circle in some essential area.
In order to be heterodox, you have to fall outside the orthodox circle in some non-essential area.
Obviously, it all depends on your definition of “orthodox.” What does it mean to be orthodox?
It has more than “right teaching” tied to it. It has to do with “right teaching according to a particular established historic tradition.” In other words, there is really no such thing as a “new orthodoxy.”
However, we need to be careful here as the term “orthodox” can be defined in several ways:
1. Historic Christian Orthodoxy: This refers to the sine qua non (the “without which not”) of the historic Christian faith. This belief is held, “by all Christians, of all time, everywhere.” In other words, it is not limited to time, geographical region, tradition or denomination. Therefore, to deny a tenet of the historic Christian faith is unorthodox from every perspective. Included in this are doctrines such as the deity of Christ, the Trinity, a belief in the physical resurrection of Christ, and a belief in the physical future return of Christ.
2. Traditional Orthodoxy: This is different than historic orthodoxy as it focuses upon the beliefs that are unique to a particular Christian tradition, whether implied or dogmatized. As a doctrine develops, people began to part ways in their interpretation. Traditional orthodoxy takes time to develop since it comes primarily as a result of controversy and challenge. There is a Catholic orthodoxy, Protestant orthodoxy, and Eastern Orthodoxy orthodoxy. For example, part of Catholic orthodoxy is a belief in Purgatory and the assumption of Mary. Protestants and Orthodox do not hold that belief. Protestants believe in a sixty-six book canon (books of the Bible), Catholics do not.
3. Denominational Orthodoxy: Finally, there is a further division that can be identified as Protestants continue to further define each of these core areas. Calvinists, for example, would further define issues of salvation, election, security, and God’s sovereignty. Arminians, on the other hand, would do the same emphasizing God’s universal atonement and God’s providential sovereignty. Baptists would add issues such as believers baptism and congregational style of leadership within the local church.
So if you are trying to figure out if you have crossed a heretical line, it depends on what you mean. My thoughts are that we need to define our terms and be very careful. One can be unorthodox with regards to a particular traditional or denominational orthodoxy, but this does not necessarily make them unorthodox in the proper sense (historically).