Does prayer, as it’s taught in biblical Christianity, actually work? That all depends on what you’re looking for.

Prayer can take many forms: meditation, an expression of gratitude or joy or anguish, an altered state of consciousness. All of these can be found in both Eastern and Western spiritual traditions and sacred texts, including the Bible. But perhaps the most common and familiar kind of prayer involves asking God for favors or help. Devout Christians send requests heavenward both privately, as they go through their daily lives, and as a community ritual during Sunday morning services. In fact, the Bible tells them to, and makes some concrete promises about how God will respond.

Consider the following verses from the New Testament:

Which of you, if your son asks for bread, will give him a stone? Or if he asks for a fish, will give him a snake? If you, then, though you are evil, know how to give good gifts to your children, how much more will your Father in heaven give good gifts to those who ask him! –Matthew 7:9-11 NIV

Ask and it will be given to you; seek and you will find; knock and the door will be opened to you. –Matthew 7:7 NIV

I tell you the truth, if you have faith as small as a mustard seed, you can say to this mountain, ‘Move from here to there’ and it will move. Nothing will be impossible for you. –Matthew 17:20 NIV

Again, I tell you that if two of you on earth agree about anything you ask for, it will be done for you by my Father in heaven. –Matthew 18:19 NIV

If you believe, you will receive whatever you ask for in prayer. –Matthew 21:22 NIV

I urge, then, first of all, that petitions, prayers, intercession and thanksgiving be made for all people—for kings and all those in authority, that we may live peaceful and quiet lives in all godliness and holiness. –1 Timothy 2:1-2 NIV

Is any one of you sick? He should call the elders of the church to pray over him and anoint him with oil in the name of the Lord. And the prayer offered in faith will make the sick person well; the Lord will raise him up. If he has sinned, he will be forgiven. Therefore, confess your sins to each other and pray for each other so that you may be healed. The prayer of a righteous man is powerful and effective. –James 5:14-16 NIV

If these claims are true, prayer should have tangible, important, real-world effects. For both believers and secularists, that’s a big deal, because these promises also offer some evidence about the trustworthiness of other promises made in the Bible. If I say I will cure your illness or give you money when you ask and then don’t, why would you believe me when I say I will make you healthy and wealthy after you’re dead?

Putting Prayer to the Test

Most people know that prayer doesn’t have the dramatic effects these Bible verses seem to suggest. It seems rather easy to point out that if prayer worked that well, Christians wouldn’t have needed to convert Europe and later Latin America to Christianity at sword-point; they could have simply prayed and preached, “for the word of God is quick and powerful and sharper than any two-edged sword” (Hebrews 4:12).

Alternately one might point out that the Black Plague devastated even the most devout, prayerful medieval communities, and that modern Christians, on average, live no longer than Muslims or Buddhists of comparable socio-economic status. But apologists for Christianity have always found ways to explain away discrepancies like these. Entire books have been written explaining why prayer doesn’t work like the verses seem to imply.

But does it have any effect at all?

Since the birth of the social sciences, serious academic researchers have suggested that we can come at this question through a different approach, by applying research methods to claims about prayer. Sir Francis Galton, statistician and founding father of modern psychometrics, published his first prayer study in 1872. Galton pointed out that royal sovereigns are the most prayed-for of any public figures. God save the Queen! But when he compared the longevity of kings and queens to eleven other groups of privileged people, he found that monarchs had the shortest lives. He concluded that prayer didn’t work, which had very little impact on the behavior of the praying British public.

Modern Prayer Research

In recent decades, research on prayer has focused primarily on illness and healing. Many prayers seem trivial or self-serving in a way that makes God’s lack of response easy to dismiss: please help me find a parking spot, or please help me get an A on this test, or please let my team win. But people generally assume that God cares about illness and suffering. After all, Jesus was called the Great Physician, and many of the miracle stories of the New Testament are stories of miracle cures. So a natural place to examine the efficacy of prayer is the field of medicine.

Studies of prayer in medicine vary in their design and results, and some Christian leaders point to one or another, suggesting that prayer improved a health outcome—a difference that seems inexplicable without God’s miraculous intervention. Those seeming miracles are precious because they strengthen the whole edifice of belief.

But the best evidence available suggests that there’s no there there.

The STEP Experiment

The biggest and most rigorous prayer study to date is known as STEP, the “Study of the Therapeutic Effects of Intercessory Prayer.” Funded by the faith-friendly Templeton Foundation, this decade-long inquiry applied a rigorous clinical research design including double blind with random assignment, and followed 1,802 patients who received coronary artery bypass surgery at six hospitals.

At the conclusion, Templeton, which had spent $2.4 million on the project, issued a press release:

This project applied a large-scale controlled randomized research model to contribute to a growing number of scientific studies about prayer. Previous studies had attracted widespread public attention and discussion due to claims of positive health outcomes for distant intercessory prayer in which patients were unaware of being prayed for in the context of a research study. Analysts, however, had pointed to methodological weaknesses calling these results into question. In view of both the empirical uncertainties and the potential significance of a non-null result, the Foundation’s advisory board advocated that substantial resources be put forth in order to advance methodological rigor in the design and execution of a new “blue ribbon standard” study. . . . the null results obtained by the methodologically rigorous STEP experiment appear to provide a clear and definitive contrasting result to an earlier published finding (Byrd study) of a positive effect for patient-blind distant intercessory prayer in a prayer experiment involving recovery of patients in a cardiac care unit. Result: The STEP project did not confirm these findings.

In other words, when examined under the most careful research conditions possible, prayer didn’t work.

Meta-Analysis

Scientists have a set of tools for wading through contradictory research results in order to identify the best evidence available and then synthesize that evidence. Meta-analysis, as this process is called, combines results from relevant studies, often weighting them based on how rigorously variables of interest were defined, controlled and measured, and how carefully alternative explanations were ruled out.

In 2009, Leanne Roberts, Irshad Ahmed and Andrew Davison conducted a meta-analysis titled, “Intercessory Prayer for the Alleviation of Ill Health.” After discarding lower-quality research, the authors reviewed 10 randomized trials “comparing personal, focused, committed and organized intercessory prayer.” In aggregate, these studies included 7,646 patients.

Overall, the meta-analysis found no clear effect of prayer on either general clinical state or death. Four studies that looked at heart attack patients specifically found no difference in readmission to a coronary unit. Likewise, two that reported on re-hospitalization more broadly found no significant difference between patients receiving standard care and those receiving the same care plus prayer.

Five years later, Roberts, Ahmed and Davison’s review was edited and republished by the leading publisher of medical meta-analyses, Cochrane Reviews, without any change to conclusions, meaning their method withstood the test of time.

It is worth noting that the authors were not hostile to the possibility that prayer might have a measurable effect, and in fact, Roberts was an employee of the Anglican Church. But they concluded that:

“These findings are equivocal and, although some of the results of individual studies suggested a positive effect for intercessory prayer, the majority do not and the evidence does not support a recommendation either in favour or against the use of intercessory prayer. We are not convinced that further trials of this intervention should be undertaken and would prefer to see any resources available for such a trial used to investigate other questions in health care.”

But, but, but

This is the kind of language that consigns a drug or surgical procedure to medical history. But when prayer studies produce null results—or weak results at the margins of statistical significance (a far cry from those biblical promises)—researchers tiptoe, reassuring the public that their findings aren’t the last word or that results have little relevance outside of the specific conditions of the research.

When the STEP results were released, one co-author—a chaplain at the Mayo Clinic—made assurances that the study had no bearing on the efficacy of personal prayer, or prayers offered for family and friends. Bob Barth, the director of an intercessory prayer ministry in Missouri expressed optimism that future research would pan out, “We’ve been praying a long time and we’ve seen prayer work, we know it works, and the research on prayer and spirituality is just getting started.”

Other prayer defenders take the opposite tack, hastening to reassure that unanswered prayer is actually a good thing. In the words of evangelist Ken Collins, one reason God might not answer prayers immediately is that “if He did, you’d stop praying! So He delays His answers to give you something better: fellowship with Him through persistent prayer.” (Can I tell my kids and husband that this is why I ignore them so often?)

Even if unanswered prayer results in suffering unto death, Theist philosopher, Richard Swinburne insists that what might look and feel bad is actually just one more way God shows his goodness: “Although of course a good God regrets our suffering, his greatest concern is surely that each of us shall show patience, sympathy, and generosity, and thereby form a holy character. Some people badly NEED to be ill for their own sake; and some people badly need to be ill in order to provide important choices for others.”

Faced with poor research outcomes, religious leaders and theologians now argue that prayer is inherently exempt from evaluation. The Bible contains warnings against “putting God to the test,” so, of course research on prayer doesn’t work! Theist philosopher Richard Swinburne dismissed the STEP results by arguing that God answers only those prayers offered “for good reasons.” Columbia behavioral medicine professor Richard Sloan told the New York Times that “the problem with studying religion scientifically is that you do violence to the phenomenon by reducing it to basic elements that can be quantified, and that makes for bad science and bad religion.” According to this form of special pleading, apologists argue that prayer—uniquely—has an effect on the natural world that is at once enormous, important and unmeasurable. God heals people, but only if we aren’t watching and measuring.

Taking such obfuscation to its logical extreme, psychologists Bernard Spilka and Kevin Ladd argue that “scientists must be willing to acknowledge the distinctly nonscientific possibility that prayer operates ‘as advertised’ in a realm that is both nonlocal and nonphysical” (p. 169). They are absolutely right about this. Faced with assertions about a realm that is completely outside of the natural order, scientists must plead ignorance. However, so must all human beings, including theologians.

Invisible, Undetectable Results Don’t Count

Arguing that an invisible god works inexplicable magic producing undetectable effects is the theological equivalent of a desperate child saying that the Tooth Fairy ate her homework. No parent or teacher or scientist can prove she didn’t. That said, it’s important to remember that humanity’s interest in prayer stems from a desire to get what we need and want. Actions of supernatural beings that have no discernable impact on actual lives are, from a human standpoint, simply irrelevant. Prayer persists because people believe that prayer affects this physical world and their own lives.

In the mind of atheist neuroscientist Sam Harris, prayer apologists had cut themselves too much slack long before they began arguing that prayer is uniquely exempt from the scientific method. He says that even before the double blind randomized trials we had a mountain of evidence that prayer requests don’t work, and Christians have tacitly adapted to what they know but won’t admit: “Get a billion Christians to pray for a single amputee. Get them to pray that God regrow that missing limb. This happens to salamanders every day, presumably without prayer; this is within the capacity of God. I find it interesting that people of faith only tend to pray for conditions that are self-limiting.”

A God Should Do Better; So Should We

God the Almighty shouldn’t operate at the margins of statistical significance. He shouldn’t be most evident when the evidence itself is of the poorest quality, fading into invisibility as the light of scientific rigor becomes brighter. He shouldn’t need defenders who are willing to tie their reputations to expensive research that they then dismiss as irrelevant when results are disappointing. God shouldn’t need defenders who engage in rabbit hole reasoning, who insist that he moves in our world and in our lives, but only as long as we aren’t looking; or who insist that despite all evidence to the contrary bad is actually good because it must be good, because by definition God is good and he’s in charge.

Since the year 2000, the U.S. government has spent over $2 million on prayer studies without producing any result that is remotely congruent with the bold claims made by the authors of the New Testament. And yet those bold claims are a reasonable set of assertions to make about an all-powerful and all-loving, interventionist deity.

Our ancestors put forward their best set of hypotheses about how the world works, who is in charge, and how we can get what we need. They did so without the benefits of enlightenment philosophy or the methods and discoveries of science, without the global flow of information and the freedom to debate ideas. They had no way of knowing that their hypotheses would fail when examined in the light of modern knowledge and analytic capacity. But at least they knew not to simply accept and repeat whatever their ancestors had said 2,000 years earlier. Maybe we could try living up to that bar.

This article is Part 1 of a four-part series adapted from the chapter, “If Prayer Fails, Why Do People Keep at It?” by Valerie Tarico in Christianity in the Light of Science: Critically Examining the World’s Largest Religion, edited by John Loftus.