Surely the greatest possible accomplishment for a religious epistemologist would be to show how God's existence might be empirically verified. The most obvious, although certainly not unproblematic, approach to this task is to claim that perceptual evidence is available from which God's existence can be inferred. The only apparent alternative, direct sense perception of God, is ruled out by God's essential unobservability, which is implied by his essential incorporeality. But Robert Oakes, in his essay, ‘Religious Experience, Sense-perception and God's Essential Unobservability’ (Religious Studies, vol. 17, pp. 357–67), boldly suggests a third alternative. God's unobservability may preclude his being perceived directly through the senses, but there are still logically possible, Oakes says, ‘sensory detections of God's presence’ (358). To illustrate, he gives the following quote from William Barclay's The Mind of St Paul:

A great artist tells us that it was his father who taught him to see and to love beauty. His father used to take him out in the evening time…One evening there was a sunset of surpassing majesty and splendour, and at the sight of it his father stood up, removed his cap and looked at the splendour of the dying sun, and said: ‘My son, it is God.’