Other people get messages through things like Tarot Cards, the flight of birds, or the repetition of similar things (like numbers). These messages are just as valid for them as my dreams are for me. What is NOT likely is that someone will actually hear the voice of the God in their head without it being evidence of a mental illness. It is for this reason that we should take people who make that type of claim with a grain of salt.
However, if someone tells you that “Such-and-such God told me this” and then goes on to say in what way, then maybe we should not be quick to judge that person as being somehow ‘loony’ for this. For all we know they may have years of mystical practice under their belts BEFORE the God spoke. Unusual Personal Gnosis of this type should not be ignored — it may eventually be a shared understanding. After all, Hestia may actually enjoy Her cup of coffee in the morning…..