William Wildblood tackles this vital question at Albion Awakening:
On more than one occasion in my life I have been informed that because of my spiritual interests I live in a fantasy world. Even well-meaning people have told me that I should forget all that sort of thing and restrict my concerns to everyday reality. My response (internal usually, but not always) has been that it is they who live in a fantasy world. By rejecting the spiritual what you are doing is rejecting the real because the spiritual is the real, and it is the material without the spiritual that is the actual world of fantasy...
(Read the whole thing...)
This is a key question - and for some people the way-in, is to recognise the incoherence of believing that we live in a purely 'materialist' world, a world that regards only sensory-perceptible, is 'scientifically'-detectable/ measurable' things as really-real.
As a professional and vocational scientist, I very soon realised that science could not be separated from the consciousness, motivation, judgement of specific individual scientists; and indeed this has been recognised in mainstream theoretical physics for a century.
In a simple sense, science cannot validate itself by scientific means.
Yet we do (culturally) believe that (somehow) science validates science! What has happened, culturally, is that scientific self-validation is taken as a basic, structuring metaphysical assumption - we simple assume it is true, because... 'the modern world', all this stuff - and build our lives upon that assumption.
But it is easy to see that this is to give 'science' a free pass, and exempt science from scientific evaluation. It also makes it impossible even to ask what is science - and to ask when is science really being done, as contrasted with fake-science.
By regarding 'science' as intrinsically self-validating; we have created a situation when science is not just assumed to be self-validating, but is also self-defined! Science has become corrupted into expedience and careerism. Science has become the purest relativism - its arbitrariness concealed behind a complex bureaucracy, arbitrarted by funding, enforced by the state and media.
My point is that we assume that spiritual things are just made-up while materialism is plain truth; yet we know that materialism is definitely wrong.
In other words, we can coherently only dispose of the spiritual if we are also prepared to dispose of the material - the choice is between having a place for the spiritual, and the denial of any possibility of knowledge at all ; i.e. nihilism - a reality that could not be known, even if it was true.
This does not prove that the spiritual is true - it simple makes clear the massive consequences of rejecting the spiritual as we do, glibly, with some comment of its being a subjective, arbitrary 'fantasy'...
(For more on this see Owen Barfield's book - Saving the Appearances.)