I acknowledge that many believers in god are powerfully affected if they believe that they have had an experience or communication with "god".
Sadly, such experiences cannot be verified, though the behavior of the believer may be altered.
What can be verified are existential items such as love and purpose.
What I think many theists do possess that they don't use is what you say Caliber: What a person can validatefor themselves.
What they lack is the ability to draw the line between what they have proved to themselves and what they can prove to others.
If a person chooses to believe, and allows that to affect them in many positive ways, they only need to stop there and allow others to find their own way.
Unfortunately, it seems like many theists get a bad "Joan of Arc" syndrome, where they fight for "god" on her behalf. If you are going to fight for god, can we at least get a memo?
As a former JW who went way way way up the company ladder, I can tell you that there are few things that will get a person so heady, so intoxicated, as to believe that what they do in life is from the one true god. It causes a person to not consider anything else, and to make unhealthy decisions. In short, it is a dangerous way to live life.
Now, if a JW (for example) were allowed to decide to worship Jehovah, and even keep private beliefs about what will happen to non-believers, that is their right.
Where it get's dangerous is the activities promoted, not the beliefs.
Can one believe and not act on their world? Of course, and this is where it gets frustrating for theists, because the world as it is is VERY different from the "map" they have been given. (such as the bible or other sources of religious dogma)