Efficacy of Prayer

The Argument

  • Praying to God to make certain things happen makes those things more likely,
  • The only plausible explanation of the increased likelihood is that God makes some prayed-for events happen.
  • Therefore God exists.


  • The hypothesis that prayer works can be tested, just like any causal hypothesis, for example:
    • Echinacea helps prevent colds
    • Magnetic fields reduce pain.
  • The gold standard of causal tests is the randomized control group study, where subjects are randomly divided into a treatment group, receiving the agent being tested, and a control group, receiving a placebo.
  • Such tests have failed to establish the efficacy of prayer.