King James Bible Dictionary

From a Greek word signifying (1) a choice, (2) the opinion chosen, and (3) the sect holding the opinion. In the Acts of the Apostles (5:17; 15:5; 24:5, 14; 26:5) it denotes a sect, without reference to its character. Elsewhere, however, in the New Testament it has a different meaning attached to it. Paul ranks "heresies" with crimes and seditions (Galatians 5:20). This word also denotes divisions or schisms in the church (1 Corinthians 11:19). In Titus 3:10 a "heretical person" is one who follows his own self-willed "questions," and who is to be avoided. Heresies thus came to signify self-chosen doctrines not emanating from God (2 Peter 2:1).

Propagandism of, forbidden under severe penalties
1 Chronicles 5:13; Titus 3:10-11; 2 John 1:10-11

Teachers of, among early Christians
Acts 15:24; 2 Corinthians 11:4; Galatians 1:7; Galatians 2:4; Galatians 61:2; Jude 1:3-16; Revelation 2:2

Paul and Silas accused of
Acts 16:20-21; Acts 16:23

Paul accused of
Acts 18:13

Disavowed by Paul
Acts 24:13-16
Teachers, False

HER'ESY, noun [Gr. to take, to hold; Latin haeresis.]

1. A fundamental error in religion, or an error of opinion respecting some fundamental doctrine of religion. But in countries where there is an established church, an opinion is deemed heresy when it differs from that of the church. The Scriptures being the standard of faith, any opinion that is repugnant to its doctrines, is heresy; but as men differ in the interpretation of Scripture, an opinion deemed heretical by one body of christians, may be deemed orthodox by another. In Scripture and primitive usage, heresy meant merely sect, party, or the doctrines of a sect, as we now use denomination or persuasion, implying no reproach.

2. heresy in law, is an offense against christianity, consisting in a denial of some of its essential doctrines, publicly avowed and obstinately maintained.

3. An untenable or unsound opinion or doctrine in politics.