Fanaticism is typically defined as “excessive, irrational zeal.” Fanaticism can develop within a variety of different traditions, but this does not mean these traditions are in their very nature fanatical. Non-fanatical forms of various traditions do indeed exist, including non-fanatical Christianity, non-fanatical Islam, and non-fanatical secularism. For the purposes of this article, “Christian fanaticism” will be defined as “excessive, irrational zeal by professing Christians about their faith.”
It may be helpful at this point to reflect first on non-Christian fanaticism, which at times has led to persecution of Christians, and then to reflect on Christian fanaticism. First, if there is fanaticism that leads to the persecution of Christians, what should be a Christian’s response? Peter directs Christians enduring persecution of some sort (indicated in 1 Peter 1:7; 2:20; 3:14, 16, and other verses, but especially 4:1, 19; and 5:8–9) to respond in several ways. Space does not allow a full exposition of 1 Peter, but Peter’s direction in this letter to his persecuted brothers and sisters includes committing themselves into God’s care (4:19); enduring in hope in light of the culmination of salvation of God’s people at Jesus’ return (1:1–13); laying aside one’s own evil (2:1, 11–12); submitting to civil government, which is indeed given by God to rule society and to establish order and justice in it (2:13–15; Romans 13:3; Titus 3:1); living in purity and not taking vengeance (chapter 3).
As far as Christian fanaticism is concerned, we must first ask whether it is biblical. Despite the confident claims of some, it is not. We are not speaking here of zeal itself, only of irrational zeal. Proper biblical zeal is indeed highly commendable. As Galatians 4:18 states, “It is fine to be zealous, provided the purpose is good.” It is the irrational zeal which is unbiblical and sinful. We see this very clearly in what Jesus identified as the greatest commandment: “Love the Lord your God with all your heart and with all your soul and with all your mind” (Deuteronomy 6:5; Matthew 22:37). When we read “with all your heart,” we think “with all your emotion,” since present-day Western culture thinks of the heart as the seat of the emotions. But to read it this way is to misinterpret it, since the ancient Israelites considered the heart to be the seat of one’s emotions, will, and intellect. In fact, the Greek rendering of the Hebrew word for “strength” in Matthew 22:35 is “mind,” and it means literally “deep thought or understanding.” So this greatest of Old Testament commandments demands loving God not only with emotions and zeal, but also with one’s mind and intellect. Therefore, any irrational zeal, according to Jesus’ own words about the greatest commandment, is actually sin. One cannot love with all one’s mind, with deep thought and understanding, and also love irrationally.
A Christian is called to love God with all of his or her mind. Thus, political, economic, moral, legal, and scientific issues must be fairly depicted and intelligently and thoughtfully pondered. Unfairly depicting opponents and their arguments is prohibited, as is neglecting to do the hard intellectual work of deep study and arrogantly refusing the insights of trained, knowledgeable experts in various fields. Christians are sometimes guilty of this kind of indiscretion. And even worse, they can be proud of their anti-intellectualism when they ought to be ashamed. It truly is wicked, since it involves intentional rejection of one third of the greatest commandment.
The increasing frequency of both non-Christian and Christian forms of fanaticism is alarming, for although we live in a technologically and scientifically advanced age, we also live in an age of widespread ignorance. But whatever the cultural norms, fanaticism by Christians about Christianity is unbiblical, unwarranted, and has no place in our lives.