In his book Miracles Today: The Supernatural Work of God in the Modern World (2021), Craig S. Keener discusses the power of prayer. He presents numerous documented cases of people with serious medical conditions such as multiple sclerosis, cancer, and blindness (verified by physicians) who were healed of their diseases. If these cases are any indication, God has not stopped supernatural interventions in response to prayer. As Bishop Barron said, “I invite anyone who thinks that miracles are the stuff of prescientific fantasy or that these supernatural signs simply don’t happen today to pick up this book. I guarantee that he or she will be overwhelmed by the sheer number of credible accounts presented in these pages. Miracles Today is intelligently and engagingly written and will appeal to believers, nonbelievers, and honest seekers.”
Can science prove the power of prayer? Imagine the following experiment. One group of sick people is prayed for, and a control group of sick people is not prayed for. If prayer really works, we will find better outcomes when people are prayed for than when people are not prayed for. If there is no difference between the two groups, then this result shows that prayer does nothing to facilitate healing. In fact, scientists have tested the efficacy of prayer in double-blind studies just as they test the efficacy of medication.
What are the results of these studies? The published results are totally inconclusive. However, from both a scientific and a theological perspective, these inconclusive results are unsurprising.
First, from a scientific perspective, these experiments violate basic principles of experimentation. There is nothing whatsoever that prevents other people (not involved in the study) from praying for the control group who is supposedly without the aid of prayer. Friends and family of those in the control group may be praying for their healing. In fact, countless times a day faithful people do pray for those with no one else to pray for them. So, testing the effects of prayer is like testing a medication but having no way to ensure that the control group is not also receiving the medication. Without a control group not receiving the treatment, the study cannot be scientifically reliable.
God freely chooses to grant certain requests on condition that we pray for them.
Secondly, if the prayers of the righteous person are more efficacious than the prayers of the wicked (see Proverbs 15:29), the prayers of a person don’t work like the chemicals of a medication. It is better to have someone like Mother Teresa praying for you than any number of other people. But we cannot empirically verify the righteousness or sanctity of any particular person. In a medical context, the equivalent would be giving medication to patients not knowing about the purity or dosage of the medication. Absent such knowledge, an understanding of the power of a medication is not possible. So, given that we cannot know the sanctity of those who pray for the sick, we cannot empirically determine the “power” of their prayers.
Most importantly, the chemical efficacy of a medication does not depend on the free choice of an individual. A drug causes its effects automatically and mechanistically, without choice or freedom. But, if God is free, the answer to a prayer of petition does depend on the free choice of God. God freely chooses to grant (or not to grant) prayer requests, unlike the chemicals of a medication which do not choose anything. If God is free, prayers of petition do not make God act, unlike a medication that makes certain chemical reactions take place. Rather, God freely chooses to grant certain requests on condition that we pray for them.
So, in terms of the scientific study of prayer, it is important to emphasize again that prayer does not exercise an automatic causal power over God. A prayer of petition does not force God to give us what we request. God remains, always remains, absolutely free. Given this freedom, completely unlike a chemical medication acting automatically, it follows that one cannot measure the efficacy of prayer through any empirical test of causal effectiveness.
You might wonder then, what is the point of praying for someone’s healing? Why would the Bible encourage believers to pray for the sick? Why would God sometimes choose to miraculously intervene if someone prays for healing?
Although God is not like a puppet that we manipulate by prayer, God is like a parent to whom we can turn. How does this work? God chooses to answer prayer because he wants to encourage us to enter into a relationship with him, to become a different kind of person.
In a similar way, I often choose to give my children what they ask for on condition that they say “please.” If they say, “give me that right now,” I typically decline their request. What is the point of my policy? Well, I want my children to be polite and courteous people. So, if they are rude in asking, my default is not to give them what they demand. But, even if they ask politely, I don’t always give them what they ask for because I sometimes judge that it is not good to grant what they request. So too, God chooses to grant some petitions on condition that we pray for them. God wants us to become people who love, rely upon, and regularly turn to our Father in heaven.
Prayer only sometimes leads to physical healing, but prayer always works for the greater good. All prayer (adoration, thanksgiving, contrition, and petition) helps us to enter into deeper union with God. Since God is always paying attention to us, when we pay attention to God, we have mutual attention, communion together. Prayer raises our minds and our hearts to God, putting us into deeper harmony with the divine. To have a loving union with God is to have the most important thing, here and in eternity. If God is our greatest good, our ultimate hope, then prayer is always beneficial.