The mentality of fundamentalism sometimes crops up where one would least expect it; and there is no better illustration of this than the inimitable New Testament scholar, J. Gresham Machen. Machen was an outspoken critic of the fundamentalist movement. He argued with great force that Christianity is a system, not a list of fundamentals. . . . While Machen was a foe of the fundamentalist movement, he was a friend of the fundamentalist mentality, for he took an absolute stand on a relative issue, and the wrong issue at that.
Machen gained prominence through his litigations with the Presbyterian Church U.S.A. He contended that when the church has modernists in its agencies and among its officially supported missionaries, a Christian has no other course than to withdraw support. So Machen promptly set up “The Independent Board for Presbyterian Foreign Missions”; And with equal promptness the General Assembly ordered the board dissolved. Machen disobeyed the order on the conviction that he could appeal from the General Assembly to the Constitution of the church. But this conviction traced to ideological thinking, for if a federal system is to succeed, supreme judicial power must be vested in one court. This is federalism’s answer to the threat of anarchy. . . .
Ideological thinking prevented Machen from seeing that the issue under trial was the nature of the church, not the doctrinal incompatibility of orthodoxy and modernism. Does the church become apostate when it has modernists in its agencies and among its officially supported missionaries? The older Presbyterians knew enough about Reformed ecclesiology to answer this in the negative. Unfaithful ministers do not render the church apostate. . . .
Machen thought it would be easy to purify the church. All one had to do was to withdraw from the modernists; the expedient was as simple as that. . . . It was not long, however, before Machen’s true church was locked in the convulsions of internal strife. The prophecy of the older Presbyterians was fulfilled. Since Machen had shaken off the sins of the modernists, but not the sins of those who were proud they were not modernists, the separatists fondly imagine themselves more perfectly delivered from heresy then the facts justified. This illusion spawned fresh resources of pride and pretense. The criteria of Christian fellowship gradually became more exacting than Scripture, and before long Machen himself was placed under suspicion. He had not taken his reformation far enough: the church was not yet true. This time the issue was not modernism; the issue, ostensibly, was dispensationalism and Christian liberty. And before this quarrel ended, a second true church was founded.
Still, no classical effort was made to define the nature of the church. This is how the mentality of fundamentalism operates. Status by negation, not precise theological inquiry, is the first order of business. When there are no modernists from which to withdraw, fundamentalist compensate by withdrawing from one another.
Machen tried to blend the classical view of the covenant with a separatist view of the covenant people. He honored Reformed doctrine, but not the Reformed doctrine of the church. This inconsistency had at least two effects: first, it encouraged Machen’s disciples to think that the conditions of Christian fellowship could be decided by subjective criteria; secondly, it planted the seeds of anarchy. If Reformed theology could not define the nature of the church, how could it define the nature of anything else? The result was a subtle reversion to the age of the Judges: each man did what was right in his own eyes. Rebellion against the courts of the church converted to rebellion against the wisdom of the ages and of the counsel of the brethren.
— Edward J. Carnell, The Case for Orthodox Theology (Philadelphia: The Westminster Press, 1959), 114–17.