Orthodoxy: that which the New Testament calls “sound doctrine” (1 Tim 1:10; 2 Tim 4: 3; Titus 1:9; 2:1) that which rightly reflects in summary form all the teaching of Scripture and which the church is bound to believe and obey.

Heterodoxy: Greek meaning a “different belief”, is an opinion or view outside traditional orthodoxy but still not heresy. Modern-day “Sabbatarians” are “heterodox” – deviating significantly from what was originally practiced by the apostolic churches. Yet their minority opinion is still not heresy, because it does not flatly contradict an essential doctrinal or practical core of the Christian faith.

Heresy: anything that contradicts sound doctrine. It is false belief that misinterprets Scripture or that ignores some of the teaching of Scripture, or that incorrectly puts together all the teaching or Scripture. The church is to shun heresy and seek to correct its errors (e.g., Titus 1: 9). Example: denial of the divinity of Christ (Arianism) is heresy. The modern incarnation of Arianism is Jehovah’s Witnesses.

Apologetics defends orthodoxy by exposng and attacking heresy. But we must be careful not to classify everything that we may disagree with as heresy. There is room in the Body of Christ for disagreement on many issues———see the post on theological triage. Heresy relates to doctrine that falls into the “essentials”, i.e., things that one must affirm to be a Christian. Sometimes, Christians wrongly classify virtually everything as “essential”. In my experience, Christians that have been exposed to the wonderful diversity in the global and historic church, tend to be more discerning in their grasp of the essentials. On the other hand, those who have been “cocooned” in one church or denomination all their life with minimal or no interaction with Christians from other churches and denominations . . . or the historic church . . . often tend to be more rigid in their understanding of essentials, embracing some doctrine as essential, that is not truly essential. We stand on the shoulders of those who went before us. We need to engage with the historic church; we ignore the teaching of the historic church to our own detriment. We have 2,000 years of wisdom that we are privileged to avail ourselves of.

Know what hills are worth dying on or you risk developing a reputation as a “heresy hunter” (not a good thing.) As Daniel McCoy, PhD in theology and professor at Ozark Christian College describes heresy hunters here, “This is the guy who watches the words of fellow Christians hawkishly in order to confirm that, yep, they’re a heretic. I knew it. I knew they weren’t one of us. Hey everyone! Guess who’s been a wolf in our midst! That’s a pretty dark way to seek a dopamine rush.”