I, and many of my friends, have stated that during prayer they were given specific commands or information, which they followed. The details were often surprising, often things we had no way of knowing, and always accurate or impressive in some way. Two friends were given GPS-style directions to places they'd never been before or even heard of. Several friends were told to give certain items to certain people; those people consistently reported dire need for those exact items. Several friends have been the recipients of such gifts -- for example, a guy none of us knew showed up at our church with hand-painted blue figurines from a particular Warhammer faction saying God told him to give them to a church; this was the exact set of figurines a friend had asked for as a Christmas gift, in the right color, which his family could not even remotely afford.
Certainly, in order to convince you or some other outsider I'd need independently verifiable evidence. Otherwise you can argue we're lying or hallucinating. But the question I asked is about someone in my position -- how should I weigh the evidence? I know I personally am not lying. I trust every one of my friends whose stories I've referenced. Most are college educated, including several with graduate degrees in technical fields, and none are prone to jump to conclusions. I have no indication (aside from these stories) that any of us suffer from hallucinations, paranoia, or other psychological issues; it's not like the guy on the back of the bus talking about alien abductions and lasers burning his legs and not knowing what city he's in.
You might be inclined to say that the data isn't statistically significant, that it's cherry picked. But I'm a mathematician; I know some things about data. Many of the experiences I'm talking about are very low probability. When people cherry pick low probability events from a broad data set, a particular pattern emerges: for every perfect hit, there are an order of magnitude more borderline hits, and another order of magnitude more near misses. For every Warhammer figurines story, there would be a dozen "God told me to give this tractor to your church" "we don't need a tractor but I guess we'll take it and let it sit for years until we eventually sell it" stories -- but I've asked around, and nobody has stories like that. There are no borderline hits or near misses; every experience my friends have been able to call to mind has been a perfect hit.
You might be inclined to argue that it's not actually God, but some other source -- white noise, ghosts, telepathic space aliens, the devil, or some combination. Whatever the source, it has the attributes of always being right, knowing or being able to influence the future, viewing love, compassion, and truth as tremendously important, and representing itself as Yahweh to me and my friends. While I cannot prove it actually is Yahweh (after all, it could be very lucky white noise), wouldn't it be reasonable for a person in my position to call it Yahweh until given good reason not to?
My earlier contention was that if someone I trust as God's follower were to report Him telling them X, and then X turned out wrong, that it would disprove my theory. Consider the above discussion to be a more detailed version of my theory -- I would certainly have to reject the theory as currently understood (thus, it is falsifiable), and instead make significant modifications to some part of it. It would be a really, really big deal if even one of those experiences turned out badly.
I also want to reiterate: this isn't the core of Christian experience. The core is a transformed life. This is stuff that just happens from time to time and is kind of cool, but God doesn't seem terribly interested in trying to use it as "proof". That's the context in which I originally brought it up -- demonstrating that the modern actions I've seen God take, like the ancient actions in the Biblical record, are more about Him accomplishing some specific goal than about impressing anybody.
> "I'm sorry for all the stuff that's messed up ... -Yahweh"
I previously noted that some people who have been faced with overwhelming evidence of the existence of God still choose not to follow Him. My wife, similarly, made the point that "it's not like [some people would] hate him any less knowing for sure he is real." Thus, God trying to "prove" Himself to those who don't want to follow Him is pointless, and He shows no interest in doing so.
Your above quote demonstrates this perfectly. Even if God proved His existence, you consider Him to have messed up or to have done a poor job. I've heard others call God bigoted, intolerant, cruel, petty, and a number of other perjoratives. If the God you say such things about proved Himself to be real, it wouldn't change the fact that you think He kind of sucks. So what would be the point of God proving Himself to you?
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With the big stuff out of the way, a couple of minor points:
> "copies of copies of translations of copies by anonymous authors of which we have no originals"
Any decent modern Bible translation goes directly from the original languages. It's not copies of copies of translations of copies; it's just translations of copies. More accurately, it's usually translations of scholarly reconstructions -- since we have copies from such a wide geographic area, we can actually do a really good job tracking down even very minor changes and making reasonable, evidence-based determinations as to the most likely original. (The process of making such determinations is called "textual criticism"; look it up if you're interested.) This is generally considered a solved problem.
> "the lives of the members of the WBC have indeed been perverted by Christ"
At best, their lives have been influenced by an extremely distorted misunderstanding of Christ. They certainly haven't been transformed by an actual, direct interaction with Christ; they certainly haven't experienced the supernatural change of character that I referenced as core to Christianity. They certainly don't display attitudes that are remotely similar to Christ.
> "who is authorized to practice it?"
I don't know if anybody presently has the authority to practice either healing or exorcism. I don't see any indication from the recorded instances of it in scripture that God would allow it to happen as part of an ego-driven "proof" to a group like JREF. I also don't see any reason to think that someone who could perform those things would be interested in JREF's money.
> "even if all Christians did believe in the same core beliefs, doesn't mean that you agree on what parts of scripture trumps other parts of scripture"
Right. That's what I've been saying all thread long. That's why I'm a pacifist and my wife was a defense contractor -- a tiny disagreement on which of two statements has the higher priority.
I think it's actually a good thing. I think God is interested in developing mature followers who weigh and consider and make tradeoffs. He wants us to grow, not to stagnate.