Some people claim to have a strong sense of being in a “strong, loving relationship with God.” I can’t say that I have anything like this myself. Perhaps other people are in communication with divinity — perhaps not. As a mere cultural survey, the authors never attempt anything like a rigorous analysis of the argument for God’s existence based on religious experience — nor would they, given that the purpose of the document was simply to survey the cultural landscape. The report simply indicates a statistical correlation between those who believe they are in a “strong, loving relationship with God” and those who “report few mental health issues” (which would be an instance of John Stuart Mill’s Method of Agreement) — and, further, a statistical correlation between those who express more “ambiguity in their relationship with God” (whatever that comes to) and those who “report more mental health issues” (which would be an instance of John Stuart Mill’s Method of Difference). So, how is this to be analyzed? To begin, it would seem to suggest that those who believe that there is a deity who loves them have a belief that promotes mental health in some way (i.e., the Method of Agreement) and that those who lack this belief lack a belief that promotes mental health in some way (i.e., the Method of Difference) — just as when all those who had fish at some given restaurant got food poisoning and all those who didn’t have the fish at said restaurant didn’t get food poisoning would suggest (via Mill’s Methods) that the fish was the cause of the food poisoning. So, if the study is correct (and, sometimes, studies like this get overturned), then we have some weak empirical evidence that certain sorts of beliefs are conducive to certain kinds of mental health and that lacking those beliefs is not conducive to certain kinds of mental health.
The question that I would ask is this: “Does this translate into some sort of positive empirical evidence for the existence of God?” I think that the answer to this is “no” — or, at least, “not without a lot of additional careful argument and evidence.” It certainly isn’t some sort of easy slam-dunk victory that it may be taken to be by some theists. Without some argument for thinking otherwise, there is no reason that the mere fact that a belief (be it a positive theistic belief, an ambiguous theistic belief, or a non-theistic belief) is statistically inclined to promote mental health is (in itself) a reason for taking that belief to be true. In order to determine whether or not such beliefs could be taken as having evidential value with respect to the existence (or nature) of God, one would have to have a better handle on arguments from religious experience more generally.
For a negative assessment of arguments from religious experience one could look at Cornman, Lehrer and Pappas’s book, Philosophical Problems and Arguments: An Introduction (Hackett; 4th Edition, 1992), pages 211-212 and Chapter 10 of J.L. Mackie’s book, The Miracle of Theism: Arguments for and Against the Existence of God (Oxford, 1982). For a positive assessment of the argument from religious experience see William P. Alston’s Perceiving God: The Epistemology of Religious Experience (Cornell University Press, 1991) and Keith Yandell’s The Epistemology of Religious Experience (Cambridge University Press, 1994).
-Dr. Robert Sloan Lee