Jesus sharply criticized the religious extremists of His day, the Pharisees and the Sadducees. The Pharisees, labeled as casuists, were drawn to extremes to justify themselves and make points in arguments. They focused intensely on minor issues, often ignoring larger, more significant matters. This tendency to make much ado about nothing, as exemplified by their straining at gnats and swallowing camels, reflects their unbalanced approach to doctrine and lifestyle. Such behavior is dangerous as it can lead to a quick and easy slide into a mindset of justification and self-righteousness.

Zeal is a good servant but a bad master, just as fire is. Zeal and sincerity are wonderful, but they are never meant to be in control, and when they are, failure follows. Zeal that is not governed by wisdom and understanding leads to fanaticism, cruelty, and persecution, and it has been one of the most devastating influences in the long history of the church. Zealots assume that being zealous means being right, but a person can be sincerely wrong and zealous in a false cause. Muslim terrorists are emotional zealots without wisdom or real understanding. The fool is governed by zeal, rushes ahead without considering consequences, and is impatient, seeing only one thing at a time and blind to everything else. The fool's quick results do not last. Saul, later the apostle Paul, is the example: he persecuted Stephen and dragged believers off to prison, certain that his sincerity proved him right. God confronted him and changed his mind, and the same energy then served Christ. Zeal is to be a hired servant, not the master. Facts are gathered patiently, weighed, and tested against God's eternal principles, and only then is the decision carried out with all vigor. The Christian is therefore governed by the truth of God, not by excitement, enthusiasm, or impatience, and carries out what is right instead of determining it.

Fanaticism is often viewed with suspicion in our culture. A person who displays too much enthusiasm for a cause is considered suspect, possibly trying to sell something or having an ulterior motive. Such individuals are labeled as true believers or fanatics, seen as unreasonable or a bit off. This perception stems from numerous examples of overzealous behavior that have given zeal a bad reputation. Fanatics are often perceived as hucksters or charlatans, their enthusiasm dismissed as an act or as being overly idealistic and out of touch with reality. Their zeal is seen as mindless or overly emotional, making them appear foolish.

Fanaticism appears as a form of idolatry, in which the passion and devotion that belong to God alone are misdirected onto something else. John's closing warning, "keep yourselves from idols," is aimed not at carved images but at false ideas, obsessions, fanaticisms, and misdirected passions. An idol is anything that holds a controlling place in life, anything that moves, arouses, or attracts a person in an obsessive way, or anything given excessive time, energy, money, and devotion. Examples include people who go beyond patriotism to fanatical devotion to their country, the mystified following of political leaders and the state, and the worship of performers, careers, children, or even one's own religion, church, leader, or pet doctrine. Cars, which many people fanatically love and care for, are also cited as objects that have no power in themselves. Behind all such devotion lies self-centeredness, since the greatest idol is self. Scripture treats this as a grave sin, with Colossians 3:5 equating covetousness with idolatry, and Ephesians 5:5 and Galatians 5:19-21 warning that idolaters will not inherit the kingdom. The remedy is to guard the mind actively, remembering that believers belong to God, that their citizenship is in heaven, that nothing temporary is worthy of worship, and that only God deserves full devotion.