This is an interesting topic. I think there are degrees to which one understands what this means that has to be taken into account. In principle when someone says God speaks to them, that's not invalid. That can be as you cite a "certain feeling." That can be a certain clarity of thought, a strong intuition, a sense of "knowing" with the heart, and so forth. But when someone interprets this as a dictation of absolute authority this is where things can start becoming a little problematic, delusional thinking, as you point out.
The way this is phrased as a "hotline to God" suggests that God is seen as a wholly external entity who sends memos down to you through a pneumatic tube like pulling up to the drive through of a bank. In how I would speak of it would be in a more valid sense that you are simply in touch with the divine in yourself, and it allows you to see things in a certain higher perspective than what you normally rely on in trying to figure crap out with the analytical mind alone. Sometimes we do better not relying on our own understanding we can grasp with the mind, but rather simply allowing insight to "come up" to us from deep within us. That phenomenon is often taken as a type of "magic" by people, or in the mythic sense, "God speaking to them".
If it is a valid internal sense, that's like asking how someone knows they are in love with somebody. "How do you really know you love her? It could just be your hormones telling you it's love because you want to get laid." That's a valid question, but it is really a matter of a one's own maturity to be able to know in themselves the difference between the two. No external authority or measuring stick or test can confirm that to the person. It has to do with their own degree of self-awareness. It has to do with their own interior
confidence in knowing themselves. Like someone who is matured can more easily recognize the difference between lust and love in themselves, it's the same thing when it comes to God "speaking" to them.
To run off half-cocked claiming you got a "special message", is like the teenager who feels his hormones kicking in imaging he has been sent by destiny his future wife in the first girl he meets. It's a very black and white interpretation and understanding which understands
nothing of the subtle and nuanced nature of reality.
I like the analogy of relating this to love. Just exchange the word love for God, and it kind of answers itself in how it works.
This is where maturity, self-awareness, life experience, self confidence, and all that kicks in. It's the same thing in knowing yourself, learning how to trust how you know things in anything else you do in life. The only difference is that is an aspect of ourselves many are simply unaware of, and hence inexperienced with. How do you know? Learn to know that part of yourself and how to utilize and integrate it into how you function in life. That's how.
The delusion or fantasy part of it is not necessarily in the fact of it, but in the interpretation or translation of the experience itself. The experience can be entirely valid, but how the mind translates it could be in fact problematic, even dangerous if they have wiring-problems between their subconscious and conscious minds. It's like when you tell someone they should practice meditation. They really need to able to deal with going into those places. It's the same with the divine mind, the emergent subconscious to give it an interesting term.
"Accurate" is an interesting criteria to impose upon it. Isn't it like asking you sister who says she's fallen in love with someone, "How can you be sure your feelings are
accurate"?
