Our most rigorous rational thinking is shot through with various forms of faith. Even skeptical doubt always contains an element of belief.

In his essay “The Critique of Doubt,” Michael Polanyi argues that doubt and belief are ultimately “equivalent.” Why? “The doubting of any explicit statement,” he writes, “denies [one] belief . . . in favor of other beliefs which are not doubted for the time being.” You can’t doubt belief A except on the basis of some belief B you’re believing instead at the moment.

So, for example, you cannot say, “No one can know enough to be certain about God and religion,” without assuming at that moment that you know enough about the nature of religious knowledge to be certain about that.

Doubt Your Doubts 

Some years ago a man began attending our church. He had begun life with a general belief in God, but he had been assailed with doubts during his college years and had lived for decades without any religious faith. After a number of months of attending our congregation he told me that faith in God was looking much more plausible to him. When I asked how that was happening, he said a turning point had been a talk he heard me give on “doubting your doubts.” He said, “I had never realized there had to be some faith under my doubts. And when I looked at the things I did believe, I discovered I didn’t have good reasons for them. When I started to examine some of the bases for my doubts, faith in God didn’t seem so hard.”

What does it mean to do that? As I got to know this man and he became a friend and eventually a member of my church, I went through the series of the things that had triggered his first doubts. Later I discovered an atheist blogger who made an almost identical list:

The first cause that plants the initial seed of doubt varies from person to person. However, some of the common reasons include: meeting a real atheist and finding that they are not the immoral, unhappy misanthropes the believer has been led to expect; witnessing a good and faithful fellow believer suffer horribly seemingly for no reason; witnessing institutionalized corruption or hypocrisy in the believer’s religious hierarchy; realizing the basic unfairness of the doctrines of hell and salvation; or finding an unanswerable contradiction or error in the believer’s Scriptures of choice.

Let’s look at each of these occasions for doubt—and how my friend eventually responded.

1. Meeting a real atheist who was not an immoral, unhappy misanthrope.

This doubt is based on the implicit belief that religious people are saved by God because of their goodness and morality. If that’s the case, then atheists by definition ought to be bad and immoral. When he learned the biblical teaching that we’re saved only by undeserved grace, not by our moral character, he realized that there was no reason why an atheist might not be a far better person than a Christian. The belief under his doubt crumbled, so his doubt went away.

2. Witnessing a good and faithful believer suffer horribly for no good reason

This doubt stems from a belief that if we human beings can’t discern a sufficient reason for an act of God, then there can’t be any. My friend came to realize this assumed that, if there was an infinite God, a finite mind should be able to evaluate his motives and plans. He asked himself how reasonable it was to believe that, to have such confidence in his own insight, and the doubt began to erode.

3. Witnessing corruption or hypocrisy in a religious institution.

This might be the most warranted basis for doubting the truth of a particular faith. But my friend realized the moral standards he was using to judge hypocritical believers came mainly from Christianity itself. “The worst thing I could say about Christians was that they weren’t being Christian enough. But why should they be, if Christianity wasn’t true at all?”

4. Realizing the basic unfairness of the doctrines of hell and salvation.

This doubt, my friend said, largely came from the underlying beliefs of his culture. He had a Chinese friend who didn’t believe in God but who said that, if he existed, God certainly would have a right to judge people as he saw fit. He then realized his doubt about hell was based on a white, Western, democratic, individualistic mindset that most other people in the world don’t share. “To insist that the universe be run like a Western democracy was actually a very ethnocentric point of view,” he told me.

5. Finding an unanswerable contradiction or error in the Scripture.

This doubt, my friend said, was based on a belief that all religious believers had a naive, uncritical trust in the Bible. “Since coming to your church I realize there have been a thousand PhD dissertations written on every single verse, and for every contention that one verse contradicts another or is an error, there are ten cogent counterpoints.” He rightly lost his faith that he could ever find a difficulty in the Bible that was “unanswerable.”

Polanyi is convincing that both pure objectivism and pure subjectivism are self-defeating and ultimately impossible to hold. The objectivists can’t account for the host of values they unavoidably know but that can’t be proved. And the subjectivists make their own assertions meaningless and contradictory. Where do they get the certainty of knowledge necessary to say that no one has the right to be certain?

Contemporary secularity, then, is not the absence of faith, but is instead based on a whole set of beliefs, including a number of highly contestable assumptions about the nature of proof and rationality itself.

Editors’ note: This is an adapted excerpt from Tim Keller’s new book, Making Sense of God: An Invitation to the Skeptical (Viking, 2016) [20 quotes | interview | review].