It is not only chronic neurological dysfunction that can cause religious and supernatural beliefs. Some of the founding experiences can be based on single neurological events such as isolated strokes or seizues. Many types of fit do not involve the motor area of the brain, so do not result in obvious, physical signs of fitting. They can be purely sensory in nature, involving sights, sounds and feelings that range from subtle through to overwhelming.
“Partial seizures can [...] cause clonic movement of part of a limb [, ... or] may trigger an abnormal sensation, or aura, such as an odd smell or sparkling lights. Most bizarre are the partial seizures that elicit more well-formed auras such as déjá vu (the feeling that something has happened before) or hallucinations.”
"Neuroscience" by Bear, Connors and Paradiso, p464
William James remained convinced that St. Paul was converted to Christianity by a vision that was the result of a lone seizure.