What is heresy?
As implied above the opposite of heresy is orthodoxy. A doctrine is true if it agrees with the Bible (2 Tim. 3:16-17; 2 Pet. 1:20-21). However, regarding Christianity heresy it is any belief, philosophy, or idea that is in contradiction to the faith once delivered to the saints (Jude 1:3). So, within the context of Christianity, a heresy is that which deviates from biblical teaching (cf. Col. 2:8; 1 Tim. 1:3-6; 2 Pet. 2:1; 1 John 4:1-6).
There are different degrees of heresy or false teachings. Paul ranks certain heresies with seditions (Gal 5:20). In Corinthians we observe that it leads to a division in the church (1 Cor. 11:19). And in some instances, it is a person who follows his own self-willed questions (Tit. 3:10). Some false teaching is completely destructive (2 Pet. 2:1), while other error leads to only temporary disagreements (Acts 15:36-41; Gal. 2:11-14). Also see 1 John 4:1-6 and 1 Timothy 1:3-6.
Though there are many, here are some modern day examples of heresies: (1) many of the teachings of the Word of Faith movement; (2) the Jehovah's Witnesses which deny the doctrine of the Trinity and the deity of Jesus Christ; (3) Mormonism which believes God is an exalted man from another planet and that man can become a god; and (4) any denomination or anyone that teaches that salvation is by works and not grace alone.
Scripture pronounces condemnation upon all false doctrines and false teachers (see, Gal. 1:8-9; 1 Cor. 16:22; 2 Cor. 11:13-15; 1 Tim. 1:18-20; Tit. 3:9-10).
Dr. Joseph R. Nally, Jr., D.D., M.Div. is the Theological Editor at Third Millennium Ministries (Thirdmill).