When most outlandish claims are made, there is a reasonable method of discerning whether or not they are true. In the case of people making claims to knowledge that they should not have access to, these claims are easily testable and always found wanting. Dowsers, Psychics, ESP-ers, and so forth, have been subjected to double blind tests and failed miserably. This is not the case for people who claim to speak to the god of the Bible however.
When one claims that they talk to Yahweh, we cannot test this claim because of what I like to call the ‘Cop-out’ clause of the Bible. “Do not put the Lord your God to the test” (Luke 4:12). We aren’t allowed to ask this god to verify his existence by manifesting, or by consistently answering prayers, providing believers with accurate foreknowledge of events that no one else could have predicted.
On top of being forbidden to ask for verification of existence, belief without evidence is also praised. “Blessed are those who have not seen and yet have believed” (John 20:29). It seems awfully convenient as a belief system to require that it be taken on faith and not questioned. Doubt is tolerated, but frowned upon, evidence and observation are maligned. I simply cannot accept these positions. Blind faith is a terribly ironic gift to give to the creator of human intelligence.