Well, in one way they might: there is a non-material realm. Only they've got hold of the wrong part of it.
Two podcasts on Truthxchange shine some light:
Karma Summit report by Pamela Frost
The first podcast has a great summary and rebuttal of 'mindfulness' at about 30:00: what it is and what the scriptures give us contrary to it.
The second has a report of the 'fairy cosmology' (at about 35:00).
This set me to thinking of the importance of Genesis 1-2. This account places the creation in human history (via the 'days'), personalises it (the God who speaks, acts and evaluates..in the same days that we do, showing himself active and present in our history), and demonstrates that the foundation of reality is personal thought: God's. This enables great evangelistic conversations with pagans who probably are aware of the immaterial realm; but the wrong territory within that realm.
Along these lines, we can handle easily detractors who seek to lampoon the scriptures in the report of the talking snake and the talking donkey.
Both are examples of the unseen reality breaking through into the material realm. But this happens all the time. Every time we speak, the unseen realm of our soul: our minds producing ideas and propositionally communicable content) breaks through into the material realm.
We use propositional content to communicate and to do. To give effect to our will.
Yahweh showed that he created a communicable and rationally understandable cosmos with his use of propositional content. A demonstration to us that we engage with 'real' reality!