Is Faith Irrational?

Some years ago on one of his broadcasts, Bill Maher defined faith as “the purposeful suspension of critical thinking.”1 Similarly, Richard Dawkins, Neil deGrasse Tyson and others have defined faith as “believing something in the absence of evidence.”2 But are these definitions of faith accurate?

In preparation for a lecture I recently gave on this topic, I decided to check the world’s foremost authoritative source for all things pertaining to the English language, namely, the Oxford English Dictionary. Featuring 20 volumes and over 21,000 pages of content, the OED is not the typical dictionary you are likely to find in an average household. But thankfully, it is now accessible through an online subscription, so I created my own account, and began investigating the true meaning of the English word “faith.”

One thing that becomes clear with an exhaustive dictionary of this kind is that just about every word in the English language happens to have multiple definitions. And, as it turns out, the word “faith” is sometimes used in a variety of ways. Sometimes it refers to an oath of loyalty (as with “a good-faith promise”), but it can also refer to a system of religious belief, such as “the Muslim faith.” But among all the varying definitions I was able to discover in the OED, one I was not able to find was the idea that faith is “believing something in the absence of evidence.” In fact, what I actually found was the complete opposite. According to the OED, one of the definitions of faith is this: “Belief based on evidence, testimony, or authority.”3

Among the citations included as an example of this definition of “faith” is a selection from a book by Isaac Watts written in 1725 titled, Logic, or The Right use of Reason in the Inquiry after Truth. Here is the relevant passage:

When we derive the evidence of any proposition from the testimony of others, it is called the evidence of faith; and this is a large part of our knowledge. Ten Thousand things there are which we believe merely upon the authority or credit of those who have spoken or written of them. It is by this evidence that we know there is such a country as China, and that there was such a man a Cicero who dwelt in Rome. It is by this that most of the transactions in human life are managed. According as the persons that inform us of any thing are many or few, or more or less wise…and credible, so our faith is more or less firm or wavering, and the proposition believed is either certain or doubtful…4

Let me ask you this: Have you ever been to Antarctica? If not, why do you believe it really exists? Well, if you think about it, you likely believe in the existence Antarctica because of the evidence of so many trustworthy witnesses who have written and spoken about it, and they have never been contradicted. According to Isaac Watts, faith is not believing in something in the absence of evidence, but instead rests on the credibility and trustworthiness of others. And as he states, the more witnesses you have, and the more credible their testimony, the more firm you will become in your faith.

In this light, faith is an entirely reasonable and rational thing. In fact, it is something we can not live without. I discussed this with Australian historian and NT John Dickson a couple of years ago, while I was hosting the WHI, and here is what he had to say during that interview:

Faith, in its original meaning, really comes down to confidence or trust. That’s the root idea of the word. The idea that it’s sort of blindly accepting things without evidence is a brand new definition in the history of the world. You can actually date when this started to happen, when people started to use faith as “believing things without evidence”—it was in the 1800s. Now, I have never looked through the microscope at the things biologists tell me are going on in cells. So everything I know about the nature of the cell I got from my science teacher and from the science textbook—and I accepted it! So even someone like Richard Dawkins…is relying on his buddies in physics to know about the speed of light or the cosmic background radio waves that are detected. He’s never actually gone and tested that himself. He’s relying on testimony from academic journals or his friends down the road in Oxford, he’s relying on their testimony. He judges them to be worthwhile, valuable, trustworthy, and he believes it.5

In addition to using the OED, another way of verifying this point is by using the Google’s Ngram viewer, which is a tool that charts the occurrence of words or phrases in all the books Google has scanned from the 1500s to the present. So if, for example, you type in the popular phrase “leap of faith” you will see that it does not actually come into use until the 1920s.6

Now, I was able to find one section of the OED that defined faith as the “belief or confidence…without any evidence or proof.” But, as it turns out, this is the definition that appears under the phrase, “blind faith.”7 The word blind, you see, is the key term of this phrase, since it ends up modifying the kind of faith that is involved. But if faith always meant belief in the absence of evidence, why would anyone have felt the need to add this particular modifier? For if by definition, faith is a kind of blind leap, then the phrase blind faith would be completely redundant.

Another question I decided to investigate was the nature of the word faith as it appears in the Greek NT. In other words, is the original Greek word for faith similar to the English word as defined by the OED, or is it closer to the definition given by the likes of Bill Maher, Richard Dawkins and Neil deGrasse Tyson? As it turns out, the Greek word for faith is pistis, which is defined by one prominent lexicon as “that which evokes trust and faith.”8 In its verbal form it also means “to consider something to be true, and therefore worthy of one’s trust.”9 Another form of this word means “to be sure about something because of its reliability…[to] be convinced.”10 That is the way the first century Jewish historian Josephus used the word when he wrote to say, “I have demonstrated…and confirmed the truth of what I have said, from the writings of the Phoenicians and Chaldeans.”11 Aristotle used this word when he wrote to say that “True theories are the most valuable for conduct as well as for science; harmonizing with the facts, they carry conviction.”12 And a first century writer by the name of Strabo used the word pistis when he said, “This investigation…only confirms us the more in our belief.”13 In each of these cases, therefore, the Greek word for faith, just like it is English counterpart, is not viewed apart from, but is supported by evidential considerations.

Furthermore, in John chapter 10, Jesus himself says, “If I do not do the works of my Father, do not believe me, but if I do them, even though you do not believe me, believe the works themselves, so that you may know and understand that the Father is in me” (10:37-38). Here it seems clear that Jesus does not view faith as some kind of blind irrational leap, but instead recommends that people believe on the basis of what they see and hear him do.14

The problem, however, is that few seem to be aware of the distinctive nature of the Christian faith claim, including among Christians themselves. In fact, after interviewing nearly a hundred individuals at a variety of Christian gatherings over the past few months, the overwhelming majority seemed to think that faith is not something that can be established by evidence or objective considerations. To them, faith is not cognitive, it is just something you know intuitively, deep down in your heart—it is a gut thing that cannot really be explained—in fact, according to one person I interviewed, “It’s sort of like grabbing air.”

Another young Christian told me, “I think if there was not some semblance of blind trust to faith, then it is no longer faith—it simply becomes evidence.” Oddly, the well known atheist Richard Dawkins said something nearly identical to this in a public debate with John Lennox: “We only need to use the word faith when there is not any evidence.”15 So then, how is it that Richard Dawkins’ definition of faith ended up winning the day, even in Christian circles? How did faith come to be thought of as the absence of evidence? This is a question I will be exploring over the next few programs on my podcast.

According to Christian apologist Greg Koukl, this newer definition of faith as “believing in something that you cannot prove” happens to be deeply entrenched in contemporary Christianity. And so, after reflecting on this for some time, Koukl ended up concluding that we should probably stop using the English word faith altogether. In fact, in a lecture he gave titled, “Truth Isn’t Ice Cream, Faith Is Not Wishing,” Koukl said this:

I’ll go to churches and make presentations and give all the reasons why it makes good rational sense to put your trust in Jesus Christ…And then Christians will come up to me afterwords and ask, “If what you say is true, if all these facts are really so, then where is the room for faith?” And I realize when they say that have a conviction deep down inside that somehow faith and facts do not go together. You exercise faith when you do not have the facts. But that is not a biblical understanding of faith…Biblical faith is trust based on what you have good reason to believe is true.16

In my humble opinion, this confusion about true meaning of faith lies at the heart of our ever increasing secularism—because if faith in God is no more rational than believing in Santa Claus or the tooth fairy, then why should anyone bother going to church? And why should one particular expression of faith be valued over and above all the other options?

Is faith irrational? In 1 Peter 3:15, Peter famously says, “always be ready to give an answer to anyone who asks you for a reason for the hope that is in you.” If with Peter you agree that Christians can and should be able to give reasons for their faith, then I believe your faith is reasonable and rational. However, if you believe that faith is a leap in the dark for which no reasons can ever be given, then I am convinced that your faith, by definition, is irrational.

The great need of the hour is for Christians themselves to go back and to reexamine the true foundations of our faith. For example, in Acts 26, Luke records Paul’s defense of the Christian faith before governor Festus and king Agrippa, and as he was speaking, Festus told Paul that he was out of his mind and that his great learning was driving him insane. But in his response, Paul simply said this, “I am not insane, most excellent Festus; on the contrary, what I am saying is true and reasonable. For the king knows about these matters, and I also speak to him with confidence, since I am persuaded that none of these things escape his notice; for this has not been done in a corner.”

©Shane Rosenthal. All Rights Reserved.



2. You can listen to these soundbites (as well as the above quote from Bill Maher) on Episode 2 of The Humble Skeptic podcast.

3. See definition 7b of the word “faith” in the OED.

4. Isaac Watts, Logick, Or, The Right Use of Reason in the Inquiry After Truth. With a Variety of Rules to Guard Against Error, in the Affairs of Religion and Human Life, as Well as in the Sciences (J. Buckland, London, 1772) II., ii., 9. This book was first published in 1725.


6. To see an image I created using the Google Ngram Viewer, scroll down to the “Show Notes” section of this Humble Skeptic episode.


8. BDAG, 3rd edition, p. 818. This is the 1st definition that appears for the word πίστις.

9. Ibid., p. 816. This is the 1st definition that appears for the word πιστεύω.

10. Ibid., p. 821. This is the 2nd definition that appears for the word πιστόω.

11. Josephus, Against Apion, 2:1

12. Aristotle, Nicomachean Ethics, 10.1172:2

13. Strabo, Geography, 1.2:13

14. Cf. Jn 2:11, 5:36, 10:25, 19:35, 21:24. For references of this sort outside of the Fourth Gospel, see: Lk 24:48, Acts 1:22, 2:32, 3:15, 5:32, 10:39, 13:31, 22:15, 2Pt 1:16.

15. Dawkins gives this definition 8 minutes and 28 seconds into this episode.

16.Greg Koukl makes this statement 27 minutes and 57 seconds into this episode. His full lecture can be ordered here.


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  • Shane Rosenthal
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    Shane Rosenthal is the founder and host of The Humble Skeptic podcast. He was one of the creators of the White Horse Inn, which he also hosted from 2019–2021, and he has written articles for various sites and publications, including Modern Reformation, TableTalk, Core Christianity, and others. Shane received an MA in Historical Theology from Westminster Seminary California, and he lives with his family in the greater St. Louis area. Read more about The Humble Skeptic podcast:

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  1. Yet we have people who, despite all of the evidence to the contrary that has increased steadily over the centuries, still believe in a flat earth. OTOH, we had (and probably still have) a tremendous number of people who believed in anything and everything the gov’t or the media told them about the COVID “pandemic” despite evidence that many of the deaths were caused by weakened immune systems or underlying disorders, false reporting about COVID-related deaths by hospital staffs who either didn’t want to take the time to fill out the proper paperwork or were incented to file false reports so the hospitals would be compensated, etc.
    That door seems to swing both ways.

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