What is it that causes some people to be more religious than others? Could it possibly be that some people are genetically predisposed to have certain spiritual experiences? Is there a "god" gene?

Some people say that there is, or at least that this is what science is starting to show. In a book called The God Gene: How Faith Is Hardwired into Our Genes [New York: Doubleday, 2004], Dean Hamer of the National Cancer Institute argues that some people have God in their genes. He says: "I'm a believer that every thought we think and every feeling we feel is the result of activity in the brain. I think we follow the basic law of nature, which is that we're a bunch of chemical reactions running around in a bag" [quoted by Jeffrey Kluger in "Is God in Our Genes?" Time , October 25, 2004, page 65].

Included among those chemical reactions, according to Hamer, are brain patterns that correlate with certain religious experiences. When people are involved in a spiritual activity like meditation, for example, the frontal lobe (which focuses our concentration) is active, while the parietal lobe (which locates us in time and space) grows quiet.

Nor is Dean Hamer the only molecular biologist who has made this discovery. Andrew Newberg is doing similar work at the University of Pennsylvania, where he is studying what he calls "the biology of belief" [as quoted by Melissa Dribben in "Agnostic studies God and the brain," Philadelphia Inquirer , December 21, 2003]. According to Newberg, the human brain has a built-in capacity to experience God. Scientists from the University of California at San Diego call it "the God module" [Ray Kurzweil, The Age of Spiritual Machines , as quoted in Christianity Today , February 8, 1999, page 77].

The work of these scientists is part of a wider field of science that studies "the neurophysiology of religious experience" and is commonly known as "neurotheology." Most of these scientists are careful to say that they can neither prove nor deny the existence of God; they are simply interested in the biology of spirituality. But based on their research they claim that parts of the human brain are pre-wired to experience spiritual phenomena. To be specific, Dean Hamer has isolated the gene VMAT2 and says it is directly related to "the ability to feel self-transcendence" [quoted in Kluger, page, 66].

How should Christians evaluate this kind of research? We know from Scripture that God has "set eternity in the hearts of men" (Eccles. 3:11; NIV). But can we also say that God has put eternity into our genome?

Of course it is true that we have an embodied existence, and that this is an inescapable fact of our religious experience. Whatever religious thoughts and spiritual feelings we have take place somewhere in our brains, and it is only to be expected that there are ways of imaging such brain activity. Some Christians have embraced the findings of neurotheology. They conclude that God has deliberately designed our brains in such a way that we have the physiological capacity to experience him.

However, I doubt whether the current research really tells us very much about what it means to be spiritual, at least in any biblical sense of the word. The scientists who are doing this work operate with a narrow definition of what it means to be religious--a definition close to what you might find in Eastern religion but far from what the Bible says about true spirituality. For them religion means repeating a mantra, or doing breathing exercises, or having feelings of transcendence, and therefore these are the kinds of activities they are trying to measure in the brain.

Absent from their list of religious experiences is anything having to do with reason. One wonders what would show up on the computer screen if scientists measured the brain activity of someone listening to expository preaching, for example, or singing a hymn that is profound in its theology, or engaged in intercessory prayer.

What science cannot tell us, of course, is where any true religious experience of God comes from. Some (not all) neurotheologians seem to think that tracking brain activity explains where religious experience comes from. For example, Michael Persinger, who is professor of behavioral neuroscience at Laurentian University, calls God "an artifact of the brain" [quoted in Kluger, page 68]. But this is simply another form of scientific reductionism, of trying to reduce everything to a physical explanation without leaving room for a God of spirit and truth.

The Bible tells us where all true religious experience comes from: it comes from the secret and inward influence of God the Holy Spirit. It is the Spirit who enables us to understand the deep truths of God (see 1 Cor. 2:9-13). It is the Spirit who convinces us that we are sinners and draws us to faith in Jesus Christ. It is the Spirit who teaches us to call God "Father" when we pray (Rom. 8:15). We cannot measure the Spirit's mysterious work, but he does it nonetheless. Jesus said, "The wind blows where it wishes, and you hear its sound, but you do not know where it comes from or where it goes. So it is with everyone who is born of the Spirit" (John 3:8; ESV).

If we had the right scientific equipment, could we see what is going on in the brain of someone under the gracious influence of the Holy Spirit? Perhaps we could. But we would still be very far from explaining God's sovereign work in the hearts and minds of sinners, or understanding the Spirit's secret influence in salvation. As it says in Ecclesiastes, God has "set eternity in the hearts of men; yet they cannot fathom what God has done from beginning to end" (Eccles. 3:11; NIV).