It’s one thing to have a discussion about postmodernism. It’s quite another to meet it face-to-face and try to reason with the postmodern mind. Our friend Todd Friel endures encounters like that on a regular basis, and the results are always astounding:
Dan isn’t an isolated case. There are millions more just like him. His postmodern beliefs encapsulate the dominant mindset of the twenty-first century. In his book The Truth War, John MacArthur points out that it’s even difficult to get a clear answer on what postmodernism is since “it describes a way of thinking that defies (and even rejects) any clear definition.”
Postmodernism in general is marked by a tendency to dismiss the possibility of any sure and settled knowledge of the truth. Postmodernism suggests that if objective truth exists, it cannot be known objectively or with any degree of certainty. That is because (according to postmodernists), the subjectivity of the human mind makes knowledge of objective truth impossible. So it is useless to think of truth in objective terms. Objectivity is an illusion. Nothing is certain, and the thoughtful person will never speak with too much conviction about anything. Strong convictions about any point of truth are judged supremely arrogant and hopelessly naive. Everyone is entitled to his own truth.
Postmodernism therefore has no positive agenda to assert anything as true or good. Perhaps you have noticed that only the most heinous crimes are still seen as evil. (Actually, there are many today who are prepared to dispute whether anything is “evil,” so such language is fast disappearing from public discourse.) That is because the notion of evil itself does not fit in the postmodern scheme of things. If we can’t really know anything for certain, how can we judge anything evil?  John MacArthur, The Truth War: Fighting for Certainty in an Age of Deception (Nashville: Thomas Nelson, 2007), 10–11.
The postmodern utopia is a moral vacuum. It’s a frightening fantasy world where relativism and subjectivism reign supreme, ambiguity is exalted, and mystery is worshipped. The clear biblical parameters of righteousness and sin are reduced to mere opinions and preferences.
We don’t have to spend much time presenting the facts of the gospel before feeling the postmodern pushback. Certainty and conviction are major crimes according to the new thought police.
If you were to challenge me to boil down postmodern thought into its pure essence and identify the gist of it in one single, simple, central characteristic, I would say it is the rejection of every expression of certainty. In the postmodern perspective, certainty is regarded as inherently arrogant, elitist, intolerant, oppressive—and therefore always wrong. The Truth War, 12.
It’s important to understand that the postmodern worldview didn’t become entrenched in our culture by accident. It’s actually a deliberate revolt against the modernism that preceded it:
Modernity, in simple terms, was characterized by the belief that truth exists and that the scientific method is the only reliable way to determine that truth. In the so-called “modern” era, most academic disciplines (philosophy, science, literature, and education) were driven primarily by rationalistic presuppositions. In other words, modern thought treated human reason as the final arbiter of what is true. The modern mind discounted the idea of the supernatural and looked for scientific and rationalistic explanations for everything. . . .
Those presuppositions gave birth to Darwinism, which in turn spawned a string of humanistic ideas and worldviews. Most prominent among them were several atheistic, rationalistic, utopian philosophies—including Marxism, fascism, socialism, communism, and theological liberalism. The Truth War, 9.
So postmodernism is a great example of rightly diagnosing the disease but wrongly administering the cure. The sterile rationalism of modernity was nothing more than unbelief in academic garb. Postmodernists were rightly repulsed by it, but they foolishly thought they could dispense with rationalism by abandoning rationality. As John MacArthur points out, rational thinking doesn’t equate with rationalism.
Rationality (the right use of sanctified reason through sound logic) is never condemned in Scripture. Faith is not irrational. Authentic biblical truth demands that we employ logic and clear, sensible thinking. Truth can always be analyzed and examined and compared under the bright light of other truth, and it does not melt into absurdity. Truth by definition is never self-contradictory or nonsensical. And contrary to popular thinking, it is not rationalism to insist that coherence is a necessary quality of all truth. Christ is truth incarnate, and He cannot deny himself (2 Timothy 2:13). Self-denying truth is an absolute contradiction in terms. “No lie is of the truth” (1 John 2:21).
Nor is logic a uniquely “Greek” category that is somehow hostile to the Hebrew context of Scripture. . . . Scripture frequently employs logical devices, such as antithesis, if-then arguments, syllogisms, and propositions. These are all standard logical forms, and Scripture is full of them. (See, e.g., Paul’s long string of deductive arguments about the importance of the resurrection in 1 Corinthians 15:12–19.)
Yet we often encounter people enthralled with postmodern ideas who argue vehemently that truth cannot be expressed in bare propositions like mathematical formulae. Even some professing Christians nowadays argue along these lines: “If truth is personal, it cannot be propositional. If truth is embodied in the person of Christ, then the form of a proposition can’t possibly express authentic truth. That is why most of Scripture is told to us in narrative form—as a story—not as a set of propositions.” The Truth War, 13–14.
Postmodern hostility to propositional truth is entirely predictable. Propositions are logical statements that either affirm or deny something. They can only be true or false—never offering a neutral or middle position. However, the fluidity of the postmodern mind is unable to accommodate that kind of clarity or simplicity. Moreover, any worldview that rejects propositions ends up rejecting itself:
It is impossible to discuss truth at all—or even tell a story—without resorting to the use of propositions. . . . Ironically, to make any cogent argument against the use of propositions, a person would have to employ propositional statements! So every argument against propositions is instantly self-defeating. The Truth War, 14–15.
Thus propositional truth is essential to the Christian faith. But does that confine Christianity to a set list of doctrines that must be affirmed? Does evangelism amount to logical persuasion of the unbeliever? And are conversions caused by superior debating skill? John MacArthur answers “No” to all of those questions, arguing that gospel truths are also experiential and intimate:
There is without question a personal element to the truth. Jesus Himself made that point when He declared Himself truth incarnate. Scripture also teaches that faith means receiving Christ for all that He is—knowing Him in a real and personal sense and being indwelt by Him—not merely assenting to a short list of disembodied truths about Him (Matthew 7:21–23).
So it is quite true that faith cannot be reduced to mere assent to a finite set of propositions (James 2:19). I have made that point repeatedly in previous books. Saving faith is more than a merely intellectual nod of approval to the bare facts of a minimalist gospel outline. Authentic faith in Christ involves love for His person and willingness to surrender to His authority. The human heart, will, and intellect all consent in the act of faith. In that sense, it is certainly correct, even necessary, to acknowledge that mere propositions can’t do full justice to all the dimensions of truth.
On the other hand, truth simply cannot survive if stripped of propositional content. While it is quite true that believing the truth entails more than the assent of the human intellect to certain propositions, it is equally true that authentic faith never involves anything less. To reject the propositional content of the gospel is to forfeit saving faith, period. The Truth War, 15.
It’s impossible to address the postmodern mission field with a postmodern mindset—the gospel is a coherent message containing historical facts, and demands an absolute response. There’s simply no way to dress that up in irrational ambiguity.