In this so-called Information Age, we have more access to more data than ever before. Paradoxically, however, in the age of Photoshop and scams and phishing and the lot, we feel less and less able to trust any of that information.

We seem, despite all of our advances in both scholarship and technology, no closer to certainty than we have ever been. Is that a fatal problem for Christians trying to convince others of the truth of the gospel? Should it be a troubling concern even in our day-to-day lives?

No…and yes. Radical doubt is, indeed, provoked by the findings of leading experts in a wide range of relevant fields. But then let's see how radical faith can respond to that challenge.

One main reason for our lack of certainty is that our brains still process the world the way our ancestors did. It's not a bad way to process the world. Quite the contrary, in fact: It is generally efficient and reliable. But it is a long way from providing us certainty about much of anything.

Nobel Prize-winning psychologist Daniel Kahneman sums up much of his career in his popular book Thinking, Fast and Slow. He suggests that we typically respond to the world in something very like a reflexive mode: apprehending, comprehending, and responding to what we encounter with as little intellectual effort as possible. We therefore "process" the world, so to speak, along well-worn intellectual pathways, habits of apprehension, comprehension, and response (Kahneman uses the term "heuristics") that have served us well in the past and require little effort to traverse again.

Our natural resort to such habits, of course, helps us avoid traffic dangers smoothly, return a tennis serve accurately, and greet a stranger at a party politely. But our reliance on what Kahneman calls System 1 thinking means that we often miss opportunities to apprehend, comprehend, or respond to reality as well as we might—or ought. For on the dark side of System 1 thinking is convention, bias, even prejudice, the very opposites of insightful, creative, and independent thinking.

Indeed, System 1 thinking is "a machine for jumping to conclusions," Kahneman says. It is an awfully useful machine—indeed, we could not survive, let alone thrive, without it. But its very speed, general reliability, and relative ease-of-use means that we tend always to resort to it unless we feel we simply have to slow down and think about things in a concentrated way. Then we employ System 2, the mode of complex calculations, critical re-examination of information, and the posing of creative alternatives. Even then, however, we use System 2 only as much and for as long as we feel we need to do so. We are, Kahneman concludes, basically lazy thinkers.

Now, to be sure, one man's laziness might seem to be just another man's efficiency. But Kahneman insists, "Anything that makes it easier for the associative machine to run smoothly will also bias beliefs. A reliable way to make people believe in falsehoods is frequent repetition, because familiarity is not easily distinguished from truth. Authoritarian institutions and marketers have always known this fact." Of course we must become thoroughly familiar with something in order to understand, assess, and respond to it properly. But Kahneman's point is different: mere familiarity feels like authenticity. What "keeps showing up" in our experience we tend to read as reality, even if in fact what keeps showing up is a function of our own choices (e.g., our choice of news media) or the choices of others seeking to direct us. Indeed, Kahneman's large book bristles with warnings about how we can be nudged or even bamboozled into errors in all sorts of ways by those who capitalize on our habits and particularly our penchant for the easy thought—or, even more basically, the vague feeling—over the deliberate, demanding consideration..

Indeed, as Kahneman cautions, "confidence is a feeling which reflects [what appears to us to be] the coherence of the information and the cognitive ease of processing it." Confidence, that is, does not emerge from true mastery of all the relevant data and laborious, skillful effort to interpret it any more than it emerges from a superficial glance at the file and a breezy hop to a conventional conclusion. Confidence itself, as we all know if we just think about it, says nothing at all about the actual quality of the thing or concept about which someone, even oneself, is confident.

Stanford business professor Chip Heath and his Aspen Institute-consultant brother Dan confirm from abundant research that the ideas that make the most immediate and lasting impact on people generally have qualities that have nothing to do with their veracity: simplicity, unexpectedness, concreteness, a measure of credibility, emotional impact, and a vivid exemplifying narrative. Thus contrary ideas that are more complex, banal, abstract, equally credible, dull, and bereft of a fascinating story cannot compete—even if they have the single quality that matters: truth.

Does this sound like certain styles of advertising? Of course it does. And certain kinds of political speech-making? And, most insidious of all, certain kinds of bestselling books on spirituality and the sermons of certain kinds of superstar preachers?

2.

One might assume that those we trust as authorities can rise above the habits of the mass. Journalist David H. Freedman will keep you awake at night, however, by his account (with the wonderful title, Wrong) of just how frequently experts have been wrong nonetheless. Let me select just two stories of the many in his entertaining and thoroughly disconcerting book.

In 1997 the University of Michigan football team decided to give one of its longtime benchwarmers a shot at a little playing time in his junior year. At one point, this young quarterback had been ranked behind six others and, understandably, had considered transferring to a school at which he would have a better chance at playing.

He took full advantage of his opportunity, however, and won the starting spot. He went on to set Wolverine records for most pass attempts and completions. Yet he was utterly ignored when it came time to consider candidates for the Heisman Trophy, and even lesser awards eluded him. (He received only an honorable mention with a regional all-star squad.)

In the NFL draft, he suffered further ignominy as he was selected 199th, and only by a team using an extra pick to make up for the loss of a few players during the off-season. He was promptly ranked behind three other quarterbacks. But a year later a teammate's injury led to this young player once again getting an unexpected shot, at which point it took him only the rest of that season to become widely considered what Freedman calls "pro football's most devastatingly effective quarterback," leading his team to four Super Bowls, winning three of them, and being named Super Bowl MVP twice. That Michigan benchwarmer was Tom Brady of the New England Patriots, destined without doubt to a berth in the Hall of Fame.

But maybe Brady is the Great Exception to the otherwise infallible talent scouting of NFL teams. Freedman immediately points, as any NFL fan would, to the career of Curt Warner, another quarterback who is likely destined for the Hall of Fame and who was sent home from his first training camp to stock grocery shelves … on his way to athletic immortality.

Sports fans, however many of us there are, in our calmer moments recognize that the hunt for the next great athlete is a matter of rather limited consequentiality. The hunt for the cure for a cancer, however, is obviously of the greatest moment. Surely in the realm of medical research, the most important research we conduct, expert knowledge is sure and sound? Meet Dr. John Ioannidis, and never sleep well again.

Ioannidis, an expert in expert medical studies, has impressive credentials. Graduating first in his class from the University of Athens Medical School, he completed a residency at Harvard in internal medicine and then took up a research and clinical appointment at Tufts in infectious diseases. While at Tufts, however, he began to notice that a wide range of medical treatment did not rest on solid scientific evidence. While next at the National Institutes of Health and Johns Hopkins University in the 1990s, Ioannidis found that two-thirds of hundreds of medical studies he read in the scholarly literature were either fully refuted or pronounced "exaggerated" within a few years of their publication.

This seems troubling. Be more troubled, however, as Freedman continues:

[Ioannidis] had been examining only the less than one-tenth of one percent of published medical research that makes it [in]to the most prestigious medical journals. … Ioannidis did find one group of studies that more often than not remained unrefuted: randomized controlled studies … that appeared in top journals and that were cited in other researchers' papers an extraordinary one thousand times or more. Such studies are extremely rare and represent the absolute tip of the tip of the pyramid of medical research. Yet one-fourth of even these studies were later refuted, and that rate might have been much higher were it not for the fact that no one had ever tried to confirm or refute nearly half of the rest.

Freedman paints a horrifying picture of experts who trust their intuitions over evidence they have at hand, let alone evidence they could get but do not bother to obtain. Atul Gawande, himself a medical instructor, writes about his colleagues' frequent refusal to face basic data regarding frequent and preventable medical problems that are attributable to skilled professionals making dumb mistakes ("Unthinkable!") and compares this dangerous attitude with pilot training that early and repeatedly pounds into students' heads that they must not trust their instincts but their instruments and their checklists—in other words, the data that matter most. You might feel with every nerve in your body that you are flying level and right-side up, but if your instruments say otherwise, it is lethal arrogance to trust your expertise over theirs. You might look around the operating room at your talented and familiar team and believe without a shadow of a doubt that your patient is ready for surgery, but if the scrub nurse cannot confirm it by her checklist, you are culpably foolish to proceed (The Checklist Manifesto).

To confirm your permanent insomnia, journalist Julian Sher examines the world of forensic science and finds many instances of wrongful convictions. He points to a 2009 study published in the Virginia Law Review that surveyed the cases of 137 convicted persons later exonerated by DNA evidence, and found that in more than half of the trials forensic experts gave invalid testimony, "including errors about shoe prints and hair samples." That same year, the National Academy of Sciences published a book-length report warning that even fingerprint matches can be misleading and calling for a drastically improved approach to forensic science. So much, then, for people's fates being determined by the clear, cold, infallible judgment of the scientific expert witness.

As the world begins to shimmer ever more before our eyes and the solid ground beneath our feet threatens to evanesce, along comes historian Alison Winter to offer an entire book about the questionable reliability of Memory. What we do not readily comprehend, what does not fit within our set of presuppositions, does not tend to register with us immediately and clearly, if at all, and therefore also not in our memory. Conversely, what we expect to experience, or afterward believe we must have experienced, gets written into our memories despite what may have actually happened.

Contrary, that is, to the popular notion that somewhere buried in our brains is a perfect recording of everything we have ever experienced, Winter shows through her study of the last century of memory research that our minds instead are constantly coding what we experience as "memorable," "sort of memorable," "not memorable" and the like, according to our understanding of the world and according to our valuing of this or that element of the world.

Furthermore, our memories are plastic, and remain vulnerable to addition, subtraction, deformation, reformation, confabulation, and other processes as our lives progress and as our beliefs change, rather than being fixed, veracious "imprints" of the external world upon our minds.

Scientist and theologian Blaise Pascal anticipated our postmodern doubts as he warned,

Man is nothing but a subject full of natural error that cannot be eradicated except through grace. Nothing shows him the truth, everything deceives him. The two principles of truth, reason and senses, are not only both not genuine, but are engaged in mutual deception. The senses deceive reason through false appearances, and, just as they trick the soul, they are tricked by it in their turn: it takes its revenge. The senses are disturbed by passions, which produce false impressions. They both compete in lies and deception.

What, then, can we possibly trust in our quest for knowledge? If we cannot trust our own senses, reason, memory—or even those of the most expert experts in our society—are we simply lost in the blooming, buzzing confusion of an incomprehensible world?

In a word, yes. Yes, we are.

3.

Christian philosopher Alvin Plantinga shrugs off this storm of frightening doubt, however, with the robust common sense of his Frisian forebears:

Such Christian thinkers as Pascal, Kierkegaard, and Kuyper … recognize that there aren't any certain foundations of the sort Descartes sought—or, if there are, they are exceedingly slim, and there is no way to transfer their certainty to our important non-foundational beliefs about material objects, the past, other persons, and the like. This is a stance that requires a certain epistemic hardihood: there is, indeed, such a thing as truth; the stakes are, indeed, very high (it matters greatly whether you believe the truth); but there is no way to be sure that you have the truth; there is no sure and certain method of attaining truth by starting from beliefs about which you can't be mistaken and moving infallibly to the rest of your beliefs. Furthermore, many others reject what seems to you to be most important. This is life under uncertainty, life under epistemic risk and fallibility. I believe a thousand things, and many of them are things others—others of great acuity and seriousness—do not believe. Indeed, many of the beliefs that mean the most to me are of that sort. I realize I can be seriously, dreadfully, fatally wrong, and wrong about what it is enormously important to be right. That is simply the human condition: my response must be finally, "Here I stand; this is the way the world looks to me."

In this attitude Plantinga follows in the cheerful train of Thomas Reid, the great Scottish Enlightenment philosopher. Reid devotes a great deal of energy to demolishing what he sees to be a misguided approach to knowledge, which he terms the "Way of Ideas." Unfortunately for standard-brand modern philosophy, and even for most of the rest of us non-philosophers, the Way of Ideas is not merely some odd little branch but the main trunk of epistemology from Descartes and Locke forward to Kant.

The Way of Ideas, roughly speaking, is the basic scheme of perception by which the things "out there" somehow cause us to have ideas of them in our minds, and thus we form appropriate beliefs about them. Reid contends, startlingly, that this scheme fails to illuminate what is actually happening. The "problem of the external world" remains intractable: We just don't know how we reliably get "in here" (in our minds) what is "out there" (in the world).

Having set aside the Way of Ideas, Reid then stuns the reader again with this declaration: "I do not attempt to substitute any other theory in [its] place." Reid asserts instead that it is a "mystery" how we form beliefs about the world that actually do seem to correspond to the world as it is. (Our beliefs do seem to have the virtue of helping us negotiate that world pretty well.)

The philosopher who has followed Reid to this point now might well be aghast. "What?" she might sputter. "You have destroyed the main scheme of modern Western epistemology only to say that you don't have anything better to offer in its place? What kind of philosopher are you?"

"A Christian one," Reid might reply. For Reid takes great comfort in trusting God for creating the world such that human beings seem eminently well equipped to apprehend and live in it. Reid encourages readers therefore to thank God for this provision, this "bounty of heaven," and to obey God in confidence that God continues to provide the means (including the epistemic means) to do so. Furthermore, Reid affirms, any other position than grateful acceptance of the fact that we believe the way we do just because that is the way we are is not just intellectually untenable, but (almost biblically) foolish.

Thus Thomas Reid dispenses with modern hubris on the one side and postmodern despair on the other. To those who would say, "I am certain I now sit upon this chair," Reid would reply, "Good luck proving that." To those who would say, "You just think you're sitting in a chair now, but in fact you could be anyone, anywhere, just imagining you are you sitting in a chair," he would simply snort and perhaps chastise them for their ingratitude for the knowledge they have gained so effortlessly by the grace of God.

The burden of proof, then, is put where it belongs: on the radical skeptic who has to show why we should doubt what seems so immediately evident, rather than on the believer who has to show why one ought to believe what seems effortless to believe. Darkness, Reid writes, is heavy upon all epistemological investigations. We know through our own action that we are efficient causes of things; we know God is, too. More than this, however, we cannot say, since we cannot peer into the essences of things. Reid commends to us all sorts of inquiries, including scientific ones, but we will always be stymied at some level by the four-year-old's incessant question: "Yes, but why?" Such explanations always come back to questions of efficient causation, and human reason simply cannot lay bare the way things are in themselves so as to see how things do cause each other to be this or that way.

David Hume therefore was right on this score, Reid allows. But unlike Hume—very much unlike Hume—Reid is cheerful about us carrying on anyway with the practically reliable beliefs we generally do form, as God wants us to do. Far from being paralyzed by epistemological doubt, therefore, Reid offers all of us a thankful epistemology of trust and obedience.

Do we need that kind of radical faith, however, to counter our radical doubt?

The Bible gives us infallible truth, doesn't it? I believe it does. But I don't believe that I interpret it infallibly. In fact, I don't believe that anyone does—do you?

What about the Holy Spirit, then? Again, the indwelling of every believer by the Holy Spirit is a precious truth, but I don't see his presence guaranteeing that every Christian will score 100% on every math test—or on/in any other test, either.

We walk by faith, not by sight (II Cor. 5:7), perhaps more profoundly than we knew. We walk, trusting our senses, trusting our memories, trusting our worldviews, and—in the face of all this doubt about all these good, but fallible, gifts of God—trusting God.

God called humanity to "fill the earth and subdue it, to have dominion" (Gen. 1:28) and to thereby work with him to make the world all it can be. We can trust God to give us at least enough knowledge of the world to care for it properly, even as we try faithfully to learn more about it so we can care for it better.

God called the church to "make disciples of all nations" (Matt 28:19), and to thereby work with him to help humanity become all we can be. We can trust God to give us at least enough knowledge of ourselves and our fellow human beings to disciple each other properly, even as we try faithfully to learn more about ourselves so we can disciple each other better.

More particularly, God calls particular groups of people and particular individuals to particular ways of making shalom and making disciples. Modern societies feature such diverse elements as various levels and agencies of the state, different forms of family, businesses, schools, health care facilities, churches, missionary agencies, mass entertainment and news media, and so on. These various instances of shalom-making and disciple-making have particular ways of knowing, and particular bodies of knowledge, that are best suited to the fulfillment of their mission. Again, then, God can be trusted to provide these institutions and individuals distinctively what they need, including epistemically, to fulfill their callings.

So let's rejoice in the gracious providence of God, who always supplies our needs in order for us to fulfill his call upon our lives. He gives us, as we pray, "our daily bread"—in metaphorical terms of knowledge as well as in literal terms of nourishment.

Let's also be humble enough to realize how little we know, how little we know about the accuracy and completeness of what we think we know, and how much we have to trust God to guide, correct, and increase what we know according to his good purposes.

Do we know enough to get to work and make shalom? Yes, we do.

Do we know enough to bear witness and make disciples? Yes, we do.

Do we need to claim certainty in order to fulfill the mission of God in these days? No, we don't.

Certainty isn't on offer. But confidence—con fide (with faith)—is. Praise God! And that's enough.

John Stackhouse is the Sangwoo Youtong Chee Professor of Theology and Culture at Regent College, Vancouver. This article is adapted from his new book Need to Know: Vocation as the Heart of Christian Epistemology (Oxford Univ. Press).

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