Certain terms that get thrown around in theological conversation sometimes perplex novices. In fact, they sometimes perplex more advanced students, too. One reason is that these terms can be used in multiple senses. A word may have a more general meaning but also a more technical one. And sometimes terms get misused. Consequently, I am offering a quick tutorial summarizing definitions and usages.
Christian. Of course, the content of this word is fiercely debated. In a cultural sense, it is often used for anyone who professes the name of Christ. In its proper sense, it can be used only of persons who have trusted Jesus as Savior and who are trying to follow Him. The critical part of the definition is the gospel. A true Christian is someone who has truly believed or trusted the gospel (which is the same thing as trusting Christ) for salvation from sin. Since we cannot observe people’s hearts to know who has true trust and who is making a false profession, we understand a visible Christian to be a person who professes faith in the true gospel. Importantly, whether we speak of trusting the gospel or of trusting Christ, a large element of doctrinal content is involved.
Fundamentals. The doctrines or teachings that are essential to the gospel are called essentials or fundamentals. For example, we cannot talk about trusting Jesus without knowing who Jesus is—and that is a doctrinal question. Neither the Jesus of Mormonism nor the Jesus of the Jehovah’s Witnesses is the Jesus of the Bible, and neither is able to save. Several doctrinal points are involved in explaining Jesus’ identity, including His deity, His humanity, and His virgin birth. Each of these doctrines is fundamental to the gospel, as are multiple others.
Christendom. At some times and in some places, nominally Christian categories became so widely accepted that they influenced whole cultures and even governments. This phenomenon occurred especially in Europe and North America. Of course, not everybody who lived in these countries and cultures was genuinely Christian. Probably most people weren’t. But those places where more-or-less Christian thought has shaped the culture and civic life are collectively known as Christendom.
Orthodox. This term has been appropriated by a collection of ecclesiastical bodies in eastern Europe, western Asia, and north Africa. These churches may also be called Eastern Orthodox, or they may have a national name attached, such as Greek or Russian Orthodox. But the word orthodox properly refers to all Christians who affirm the chief symbols or creeds: the Apostles Creed, the Nicene Creed, the Athanasian Creed, and the Formula of Chalcedon. In short, to be orthodox is to be historically and biblically Trinitarian and to affirm the one-person-two-natures understanding of Christ. In this sense, orthodoxy is a broad category that includes Roman Catholics, Eastern Orthodoxy, Protestants, and even (especially!) Baptists.
Heterodox. If orthodoxy is right doctrine, then heterodoxy is erroneous doctrine. The word is applied especially to those who deny the teaching of the chief symbols or creeds. The mark of heterodoxy is a denial or false view of the Trinity or of the person and natures of Christ.
Infidel. An infidel is a person who denies the gospel while claiming not to be a Christians. The word covers approximately the same territory as pagan or heathen. Christians consider followers of Zeus, Odin, Brahmin, Mohammed, and the Buddha (among others) to be infidels. Atheists and agnostics are also infidels. Nevertheless, Christians don’t use the word much these days because it is sometimes considered derogatory. Also, Muslims seem to have co-opted the word infidel to refer to non-Islamic people.
Apostate. Like an infidel, and apostate denies the gospel. Specifically, an apostate denies at least one of the fundamental doctrines that are essential to the gospel. Unlike an infidel, an apostate still claims to be a Christian. Apostates name the name of Christ and seek recognition as Christians. Even though they claim to be Christians, however, apostates have left the faith because what they deny is essential to it. Most older, mainline denominations have become apostate.
Heretic. In the New Testament, a heretic is a professing Christian who creates divisions among believers. The term is only occasionally used in that sense today. More commonly, heretic is used as a synonym for apostate: a professing believer who denies some fundamental of the gospel. Sometimes the word is used for a person who holds any level of doctrinal error. This use of the word creates confusion. If you use the word heretic, you should probably specify what you mean by it. Not every doctrinal mistake is a fundamental error.
False Religion. A false religion is any organized presentation of or approach to God that denies one or more of the fundamental doctrines, whether it professes to be Christian or not. From a biblical point of view, Hinduism is an example of a false religion. So is Mormonism and so is Roman Catholicism (which denies justification through faith alone). Adherents to false religions cannot rightly be called Christians in the proper sense.
Denomination. A denomination is a church or group of churches that agree upon the gospel, but that disagree on lesser points of doctrine and order. The word implies that the members of these groups recognize one another as the Body of Christ, “variously denominated.” In other words, historic Baptists, Presbyterians, and Methodists, for example, recognize each other as genuine Christians, but they still organize separately to preserve what each believes is some truly biblical distinctive. The Roman Catholic Church should never be called a denomination. From its own perspective, it claims to be the one, holy, Catholic, and apostolic Church. From a gospel perspective, it cannot be recognized as a true church at all.
Cult. This word is used in two or three senses. In the most proper sense, a cult claims to be Christian while denying orthodox Trinitarianism or Christology (examples include Mormonism, Jehovah’s Witnesses, Oneness Pentecostalism, and Seventh-Day Adventism). Sometimes the word is used to designate any recent or non-traditional religious system, such as Spiritism, Theosophy, Rosicrucianism, Baha’ism, or Scientology. The word can also be used to designate religious organizations or systems that insist upon personal adherence to a leader who delivers some unprecedented insight or revelation. Even otherwise orthodox Christian groups can take on a cultish flavor when they overemphasize personal or institutional loyalty and close themselves off from outside contact.
In the foregoing, I’ve tried to describe correct uses of several terms. I’ve also suggested several common alternative uses. My goal is not to become a definition cop or to blow the whistle on mistaken usages. Rather, I hope to promote clarity in discussion by re-rooting these terms in their proper meanings.
This essay is by Kevin T. Bauder, Research Professor of Historical and Systematic Theology at Central Baptist Theological Seminary. Not every one of the professors, students, or alumni of Central Seminary necessarily agrees with every opinion that it expresses.
Now, Saith the Spirit of the Lord
Isaac Watts (1674–1748)
“Now,” saith the Spirit of the Lord,
To those who sit on earthly thrones,
“Rejoice with trembling at His word,
And at His feet submit your crowns.
With faith and love address the Son,
Lest He grow angry, and ye die;
His wrath will burn to worlds unknown,
If ye provoke his jealousy.
His frown shall drive you quick to hell,
For He is God, and ye but dust.
Happy the souls that know Him well,
And make His grace their only trust!”
