I don't see what any of that has to do with a belief that drug-induced hallucinations are not divine visions...
How does your character know anything about drugs? Hundreds and thousands of years men used plants and herbs to medicate and alter their perception of the universe, there was a time and still is in many aboriginal tribes where this reality and the other ones are of no difference, where dreams are as real as waking reality. What is the difference between a divine vision and one induced with the aid of a fruit? None to the one who experiences it.
