What does the Bible say about heresy?

By the second century A.D. it came to represent a corruption of theological truth corresponding to the distortions of false teachers: "But false prophets also arose among the people, just as there will be false teachers among you, who will secretly bring in destructive opinions [haíresis]" (2 Peter2:1). As a human construct with a strong distaste for revealed mystery, heresy cleans up orthodoxy's bad math — on the Trinity, for example (e.g. Arianism), or on the two natures of Christ (e.g. Docetism). As it is almost always an oversimplification of God's revealed mystery, heresy is a species of theological laziness. As it is almost always a triumph of human reason over divine revelation (Colossians2:8), heresy is also grounded in human hubris and hence a species of "faction" classified as one of the "works of the flesh" along with such things as licentiousness, idolatry, and envy (Galatians5:19 - 20). More than mere disagreement on peripheral matters, heresy is the opposite of orthodoxy and thus, in its opposition to the truth (2 Timothy3:8), is a denial of the one who is "the way, the truth, and the life" (John 14:6; c.f. 1 John 2:21 - 22). Heretical persons are thus to be opposed and avoided (Titus 3:9 - 11) by believers who, led by the Word and Spirit, "contend for the faith that was once for all entrusted to the saints" (Jude 3).