It all, even theory, seems to be concepts ... based on material evidence .. and objects.
I guess to be sure, that technically even material objects, even the cup of coffee in front of me, is only theoretical. Since it's not even a solid object, in the view that sees it as empty space, only partly filled by a tangle of competing atomic energies. And my brain sees it as solid, only thanks to built in theories in my brain, that are tuned to see it, predict it.
But most physical objects, though variable in many ways, are pretty stable on this world. And can be counted on as stable Material evidence for this or that theory. And especially the theory that there are real-enough, material things, objects, out there.
I guess that's where I'm headed. 1) Theories need material things as material evidence. 2) Even though even material things themselves are in some ways, hypothetical constructs, 3) still, they are stable enough to rely on. They are probably the firmest theoretical constructs we have.
4) Religionists like to point to some of that, to say it's all mental or spiritual, and is "faith" specifically. But?
Since objects are our firmest ideas or theories, by far, then they are in effect in a class by themselves. And very useful as evidence in any theory you might propose. And useful as evidence for or against, almost any mental or 'spiritual" idea or construct.
If that makes sense?
I'd add that 5) even if we do not refer so much to to "laws" any more, we do still refer to material objects, as having some substantial, evidential reality. And even our many theories about life, probably contain, are based in, objects.
So 6) even if nothing was entirely, simply material, still, nothing is entirely spiritual either. Material objects have probably always been, and likely for a long time will still remain. As therefore the firmest foundation for our ideas about life.
And the spirituality and faith that abandons that base, is very foolish.