What Does Christianity Say about the Complexity of the Brain?

“Who do you think you are?” It’s a question I have occasionally been asked, especially if I was being selfish or arrogant. But aside from asking someone why they think they have the right to behave badly, the question can take on other meanings too. In fact, a different meaning of the question is looming large these days as the world seems to be asking, What does it mean to be human? What is our nature? Are we, as the Bible says, made a little lower than the angels? Or are we instead made just a little higher than the apes? Are we bodies only, or body and soul? So we can ask again, Who do we think we are? And more importantly, who does God say we are?

Whatever else we might say about ourselves, it is clear that the brain is a central part of what makes us human. There is nothing in the world more amazing than the human brain, a marvel of complexity that far surpasses everything else in the animal kingdom. But it is even more than that. In fact, we know of nothing to rival it anywhere else in the entire cosmos – including even the most sophisticated technology humanity has invented.

Can science explain consciousness?

Aided by astonishing technology, there has been amazing progress made in understanding the form and function of the brain: how the parts are structured, which parts are associated with which mental events, how the various components interact and communicate, and more. The feature that makes the brain so amazing is its role in human consciousness, the most incredible thing in the known universe. Despite all this progress, however, we are no closer to comprehending how all that structure and function could give rise to consciousness. As philosopher David Chalmers points out, simply mapping the brain and describing the physical and chemical processes within it does not actually answer the “hard question” of consciousness: “Once we have explained all the physical structure in the vicinity of the brain, and we have explained how all the various brain functions are performed, there is a further sort of explanandum: consciousness itself. Why should all this structure and function give rise to experience? The story about the physical process does not say.”[1] We’re really no closer to answering that question than we ever were. Perhaps, as the Scriptures suggest, the spiritual aspect of our nature provides an insight that is being ignored by those who only study the brain.

Is belief in God just an evolutionary accident?

Over the past few decades, there has been a growing interest in explaining the universal tendency humans have to believe in God. The proposals are numerous. Some postulate that belief in God provides an evolutionary advantage. For example, it has been suggested that believing in God provides a reproductive advantage because religiously dedicated people make better mates due to their conscientiousness and loyalty. Others say people who believe in God make better group members because they believe there is an invisible observer who holds them to account for breaking the rules. Then there are the models that say belief in God was not selected for being directly beneficial at all, but it was the unintended byproduct of other cognitive patterns that were themselves directly beneficial. 

If people tend to see the world in patterns suggesting design, for instance, they might infer design even in things that formed randomly – like seeing faces in the clouds or the image of a saint in a potato chip. Or perhaps it is beneficial for us to think that there are agents everywhere that may be trying to harm us. In that case, we might start to imagine human or even superhuman beings that aren’t really there – beings like God. These models all suggest that one way or another belief in God is an evolutionary accident. 

But the findings of cognitive science of religion are also consistent with a radically different interpretation: that we believe in God because God designed us with the tendency to. Science cannot say which of those perspectives is right, so it cannot refute the biblical teaching that God shows himself to us through creation and conscience that we might believe. Christian teaching here seems to make better sense than the naturalist’s perspective since they end up believing that our cognitive systems are massively deceiving the majority of humanity by generating such wildly false beliefs.

Are encounters with God anything more than tricks of our nervous system?

As with general beliefs about God and other supernatural beings, there has also been a lot of research that tries to undermine the reliability of religious experiences. To be sure, there are very many reported encounters with God that result from things like schizophrenia, paranoia, hallucinations, religious delusions of grandeur, manic episodes of bipolar disorder, and more. But what about the dramatic events recorded in Scripture like the visions and experiences of people such as Abraham, Jacob, Moses, Isaiah, Daniel, Ezekiel, Mary and Joseph, Peter, Paul, John, and others? 

Such encounters with God have always been understood as authenticating their messages. But has science shown that they merely suffered from brain malfunctioning? And what about the more ordinary experiences of feeling convicted about sin, being moved to worship God, having assurance of forgiveness, developing a growing faith and confidence in God, having a prompting from the Holy Spirit to pray for someone, or even the slow process of sanctification by which God makes us more like Jesus, changing even the things we desire to be more in line with what he treasures? 

When God moves us to respond to the gospel by turning from sin and believing in Jesus, is that not the work of the Holy Spirit? In short, the answer is that the science has shed some light on a few types of experiences, such as the ecstatic feelings experienced by Buddhist monks or Carmelite nuns, but nothing that would undermine the trustworthiness of the biblical accounts or the quieter experiences of God. And even if they were able to reproduce experiences similar to those under laboratory conditions, that would not show that what Christians experience is not real – any more than being able to produce hallucinations of spiders crawling on the walls would show that there really are no spiders after all.

Is morality an illusion?

One of the more unsettling implications of viewing persons as nothing but evolved animals – collections of atoms arranged by blind, random forces – is that it does away with morality. More than any other creature in the animal kingdom, humans have a highly sophisticated sense of morality that begins to manifest itself in the toddler stage. According to a naturalist perspective of human nature, our brains were forged by evolutionary forces to endorse some behaviors and condemn others. Why? Because those behaviors were more conducive to individual and group flourishing. The claim is that it just turns out that altruism, cooperation, agreeableness, loyalty to family and community, commitment in child-rearing, and some level of sexual restraint just work better at helping humans thrive. Violence, conceit, selfishness, callousness, rapaciousness, and other “vices” simply do not have the same success. Or so it is said. 

But that seems like a very shallow and unsatisfying account of morality. Is that really all there is to it? Is the most we can say about oppression, rape, violence, dishonesty, and all other forms of wickedness that they just happen not to work as well? On a Christian view of personhood, we have the law written on our hearts, which can be understood as endorsing the reality and objectivity of the moral convictions our brains are intended to form. If our brains were formed by blind forces and not by God, we might just as easily have spurned the virtues we hold and valued those vices instead, if they worked better in helping us survive. There would be nothing real about morality.

Can we be free?

To be sure, the inner workings of the brain are still largely mysterious, but one thing seems evident: as a purely physical and chemical system, there cannot be anything except the laws of nature operating on the material of the brain. Suppose that we are nothing but our bodies and brains. In that case, every mental event we experience – making choices, deliberating, weighing our values, considering alternatives, and so forth – would really reduce down to a brain event. What the mind does would just be what the brain does. But what the brain does is simply an unfolding of the complex effects of laws of nature operating on a physical system. 

It would be no different than the scattering of pool balls on a table or the unfolding of weather patterns. Our choices would be impossibly complex to predict, but whatever occurs would be no different than any other complex physical happening. This is why atheist Sam Harris refers to us as “biomechanical puppets.”[2] If we are nothing but material beings, he is right. But the Christian view of personhood as consisting of both body and soul avoids the reductionist pitfall. We are spiritual beings as well, not just physical, and who we are cannot be reduced to rules about matter in motion.

What about science itself?

By affirming the complexity of the brain but denying its design by God, the scientists who push for the reductionist, materialist, naturalist view of human nature end up undermining their own credibility. One of the first people to notice this problem was none other than Charles Darwin. Reflecting on the implications of his Origin of Species, he said, “But then with me the horrid doubt always arises whether the convictions of man’s mind, which has been developed from the mind of the lower animals, are of any value or at all trustworthy. Would any one trust in the convictions of a monkey’s mind, if there are any convictions in such a mind?”[3] C.S. Lewis made a similar point:

"Supposing there was no intelligence behind the universe, no creative mind. In that case, nobody designed my brain for the purpose of thinking. It is merely that when the atoms inside my skull happen, for physical or chemical reasons, to arrange themselves in a certain way, this gives me, as a by-product, the sensation I call thought. But, if so, how can I trust my own thinking to be true? It’s like upsetting a milk jug and hoping that the way it splashes itself will give you a map of London. But if I can’t trust my own thinking, of course I can’t trust the arguments leading to Atheism, and therefore have no reason to be an Atheist, or anything else. Unless I believe in God, I cannot believe in thought: so I can never use thought to disbelieve in God."[4]

If, on the other hand, our brains are the product of divine design, we would have reason to put confidence in our ability to acquire knowledge. Christianity, not naturalism, is the true ally of science. It is far better at accounting for the complexity and trustworthiness of our brains. The Bible affirms that we are embodied beings, but it also affirms our spiritual nature. We are not merely bodies. It says that you are not just an animal with a brain shaped by mindless evolutionary forces, but instead are made in the image of God as a spiritual being created to know and love him. The naturalistic and Christian visions of human nature could not be more different, and how we think about the nature of our complex brains is at the heart of it. So who do you think you are?


  • 1. David J. Chalmers, The Conscious Mind: In Search of a Fundamental Theory (Oxford: Oxford University Press, 1996), 107.
  • 2. Sam Harris, Free Will (Free Press, 2012), 47.
  • 3. Charles Darwin, letter to William Graham, July 3, 1881, in The Complete Life and Letters of Charles Darwin, ed. Taylor Anderson (n.p.: CreateSpace, 2018), 136.
  • 4. C. S. Lewis, “They Asked for a Paper,” in Is Theology Poetry? (London: Geoffrey Bles, 1962), 164–65.

Photo credit: ©Getty Images/metamorworks

Bradley L. Sickler, PhDBradley L. Sickler (PhD, Purdue University) is an associate professor of philosophy and the program director for the master of arts in theological studies program at the University of Northwestern, St. Paul, Minnesota. He is the author of God on the Brain.


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