The issue of intercessory prayer is a controversial one. The idea that prayers in behalf of another can influence the health of that other person has a long history. It has been subjected to research generally leaves much to be desired.

In a mid-1960s study, Joyce and Weldon matched patients with chronic or progressively deteriorating rheumatic or psychological illness on sex, age, and clinical diagnosis.¹⁶⁹  Two groups of 19 patients each were created. The "treatment" group participants were prayed for by members of a prayer group; the "nontreatment" group served as a control. Each patient in the "treatment" group was the recipient of a total of 15 hours of prayer over a 6-month period. This was a double-blind study, in which neither the patients nor their physicians knew of the prayer "treatment." After 6 months of intercessory prayer, no difference between the two groups could be demonstrated.

Within a few years, another intercessory prayer study was reported by Colipp.¹⁷⁰  This involved 18 leukemic children, 10 of whom were randomly chosen to be the objects of prayer by the author's friends and church members. After 15 months of prayer, the "treatment" group seemed to have a slight advantage over the control group in survival (p < .10).

A third study utilizing 393 coronary patients was undertaken by Byrd.¹⁷¹  Patients, doctors, and the author were all kept "blind" in this work. The results seemed to support the power of intercessory prayer, as the 'treatment" group appeared to do better than the controls. Though this work looks impressive on the surface, many serious questions may be posed regarding its design, data analysis, and interpretation. In fact, strong challenges to the validity of all these studies can be advanced, based on the nature (and often the size) of the samples, the evaluation procedures, the methodology, and the statistical analyses. If scientific doubts are not enough, many theologians should be able to mount their own criticisms of this kind of work. We must conclude that at this stage of research on intercessory prayer, its power and significance have yet to be demonstrated.