There is a lot of talk about heresy these days.

The frequency and volume of accusations suggest that some Christians have lost a sense of the gravity of the word.

On the other hand, many believers have little to no familiarity with orthodox doctrine or the historic distortions of it.

What's needed is a strong dose of humility and restraint, and also a clear and informed definition of orthodoxy and heresy.

In the Know the Heretics series, scholar and author Justin Holcomb provides an accessible "travel guide" to the most significant heresies throughout Christian history.

Each lecture covers a simple explanation of the unorthodox teaching, the orthodox response, and reflections of contemporary relevance for application in today's world.