And what sort of mental condition does such a believer have to be in in order to "hear" God? Why don't Muslims hear God the same way? Or Hindus? Or Jains? Or Shinto?
Could "hearing voices" just be something Christians adopt and then act in their imagination to "hear" theiur God of choice? What method do you use to discern an actual voice of God is being heard versus your imagination?
27 My sheep hear my voice, and I know them, and they follow me:
28 And I give unto them eternal life; and they shall never perish, neither shall any man pluck them out of my hand.
Whoever is of God hears the words of God. The reason why you do not hear them is that you are not of God.” John 8:47
1 Kings 19:11-13
And he said, “Go out and stand on the mount before the Lord.” And behold, the Lord passed by, and a great and strong wind tore the mountains and broke in pieces the rocks before the Lord, but the Lord was not in the wind. And after the wind an earthquake, but the Lord was not in the earthquake. And after the earthquake a fire, but the Lord was not in the fire. And after the fire the sound of a low whisper. And when Elijah heard it, he wrapped his face in his cloak and went out and stood at the entrance of the cave. And behold, there came a voice to him and said, “What are you doing here, Elijah?”
In my own experience God often speaks in object lessons and impressions and amazing "coincidences."
I suspect he speaks differently to each person in the language they can understand the best. I can only remember time or two when it was something close to an audible voice... when he's speaking through the Bible it's often as if one line or verse or passage suddenly stands out, and I see something there I never did before.
He definitely speaks to me through his creation, also and through people. How do we know it's God? As Jesus said, we recognize his voice because we are his followers.