Neuroscientists, philosophers, and theologians have speculated regarding the evidential value of neuroscientific data pertaining to religious experience. However, most of the strongest speculation has come from naturalists who argue that the neuroscientific data straightforwardly “debunks” religious experience. Typically, a naturalist’s argument proceeds in two main steps. Firstly, the naturalist argues that neuroscience data provides support for a localization thesis on which religious experiences are functionally localized to a particular brain area. Secondly, the naturalist argues that the localization of religious experience supports a naturalistic hypothesis according to which religious experiences are hallucinatory. The conclusion is then marshaled against the positive epistemic status of religious experiences. The aim of this essay is to evaluate both steps in the naturalist’s argument and to proceed as follows. In the first part of the essay, I introduce the traditional localization of function methodology in cognitive neuroscience. I then defend this approach from the recent objection that it commits mereological fallacy. However, I note that anti-localization views are on the rise in neuroscience, more generally. In the second part of the essay, I turn to the evidential question. I argue that the debate between localization and anti-localization theories is neutral on the evidential value of religious experience. Rather, the primary issue concerns the causal sufficiency of brain region(s) in religious experience. Turning to the naturalist’s main argument, I show that the claim that religious experiences have sufficient physical causes does not entail that religious experiences are hallucinatory. Moreover, I show that the naturalist’s argument surprisingly depends on a crucial a priori claim about divine action. In order to make the discussion tractable, I limit discussion to theistic religious experiences and focus on just the hypotheses of theism and naturalism.