What do you associate that word with? Torches and pitchforks? Burning someone at the stake? The incessant barking of theological watchdogs? “Health and wealth” preachers? Unbelieving bishops who deny the gospel but stay on the payroll of the church?
What is heresy?
One writer defines it as “any teaching that directly contradicts the clear and direct witness of the Scriptures on a point of salvific importance.” Heresy is the kind of doctrinal error that is so serious that it redefines the gospel. Error is always costly. It dishonours God and damages the Church. But not all errors are heresies. A heretic is not someone who fails to explain adequately the doctrine of the Trinity, or that Jesus is both fully God and fully man, the nature of the atonement, or justification by faith alone. No, a heretic denies these truths and is fundamentally unsubmissive to apostolic doctrine and authority as it is given in Scripture.
Heresy is not a matter of opinion. We have an objective standard when we want to find out which theological view is correct or orthodox (meaning “right belief”), as Paul shows in 1 Corinthians 15, and which ones are wrong . In the end the fight against heresy is always won by the clear, patient, and thorough exposition of Scripture. Perversely, successful heretics themselves often claim to be truly orthodox and biblical.
Heresy is a matter of choice. It is the choice to believe a different gospel. Augustine said that heretics are men “who were altogether broken off and alienated in matters relating to the actual faith.”
A heretic chooses to tell lies about the God of the Bible because he doesn't want to tell the truth. And a heretic is someone who refuses admonition and is divisive (Titus 3:10-11). Putting it mathematically, heretics take away from the truth of the gospel (and adding to the truth always takes away from it), they divide true churches and aim to multiply new disciples.