The interesting question here, I think, is that how does one gauge "truth" from "untruth"?
If someone says "I understand internally that the universe works like this, it's a spiritual truth" then it is true that they believe the universe works in such a way, but such an assertion is not at all useful in working out how the universe actually works. Those two things are very different.
Using the phrase spiritual truth in this way stretches the usual meaning of the word
truth beyond breaking point. I think we need to use a more appropriate phrase in that case. Spiritual
truth is misleading. I'd suggest that hypothesis would be a better word. If we don't have any measurable data to support an assertion, then isn't it a hypothesis. That's a key step in advancing our body of knowledge: If x and y then maybe z - let's go see if we can find z.
But it seems framed to imply that those invested in finding truth of a spiritual nature have no data to support their paradigm.
Well, firstly, that's not how it's framed. I would suggest you're thinking that because you see the world of science in this way:
What is most often true is that the trail of evidence the spiritual seeker follows is discounted by those trained in or accustomed to dealing only with physical truth.
As I wrote before, this certainly isn't my experience when interacting with rigorous, critical-thinking individuals. The only time I see anyone discount evidence is when the topic is something utterly ridiculous such as when someone says we never landed on the moon and here's my evidence, or the earth is flat and here's my evidence. I think we can
all be forgiven in those circumstances for not wasting our time looking at the evidence. People of science would usually find it extremely disrespectful and ignorant to just ignore credible evidence. It goes against everything the world of science stands for - the core of it being the scientific method.
And secondly, I was responding to your own example of a spiritual truth, and you saying that there was no way to assemble data to support it:
my understanding of how God is literally in conscious control of every quark and raindrop. There is no way I can assemble data to support that belief.
Now you're putting forward a different scenario; one in which the spiritual seeker is in fact following a trail of evidence - well, that's science! That's all science is - make an educated guess (or maybe even a wild guess), go find out if it's true, publish your method and results. Here, we can just use the word truth in its everyday sense. We don't need to get into ontology and epistemology because the sort of thing we're talking about here is simply observable fact. If we do [whatever] will the thing turn blue or red. We do the experiment. The thing turns red. So we've revealed something true about the world - do this, in this particular way, and the thing turns red. That's all we can say. The wider process of creating a working model of the universe based on lots of these observable truths is a different matter.
This process does not deal in
absolute truths. The world of science never says "we are the authority, we get to tell you what the truth is, and
only we can discern the truth, and no-one else should even question us."
(1) But that's what some religious leaders and cult leaders and atheist dictators would say. The issue with truth is not with faith or religion or science or spirituality. The issue is about the concept of
worship - I don't mean that specifically in the religious sense of attending a church or whatever, but in the wider sense of looking to an authority who dictates the truth and doesn't offer any evidence. That concept sits at odds with the world of science which just says let's go take a look, and whatever we find, that's what we have to accept. It also sits at odds with the spiritual world as you now describe it - if you're saying that a spiritual seeker may follow a trail of evidence, that sits in opposition to anyone (religious, philosophical, spiritual, atheist) who would say that we already know the truth and we don't need to provide any evidence to support it.
(1) I am of course referring to actual science when I write "never". There are lots of examples where the world of science does this - such as not allowing women to practice science or even obtain a scientific education. But such practices are not part of the scientific method which is what I'm referring to here. It's also quite common for there to be resistance to new evidence - sometimes even scientists are entrenched in models that have worked for a long time and appear to reflect an absolute truth. But within the context of the scientific method, this is healthy scepticism. It prompts people to be even more rigorous, and do even more experiments, and eventually the world of science will accept the evidence if it keeps passing test after test after test...