Openness to spiritual experiences...with caution

After a Protestant Christian upbringing (I was a teenage organist in an Austin Lutheran Church, and took a course from theologian Paul Tillich at Harvard), my adult materialistic scientific Deric has never been able to fathom how an intellectual like Ross Douthat could be a devout Catholic. My irrational faith is in a materialism that is open to spiritual experiences and insights, but also strives to explain them in materialistic terms (as I think near-death experiences have been). I think Douthat’s recent opinion piece in the NYTimes very lucid, although I take exception to one of his pronouncements, and I would recommend that you read it. Here are some clips:

...the dissolution of the old order of American religion — the decline of churches and denominations and the rise of deinstitutionalized spirituality — means that more and more religious lives are lived in between worldviews, in experimental territory where it’s a mistake to expect coherence, theological consistency, a definite set of prior assumptions or beliefs...I want to defend the rationality of this kind of spiritual experimentation and then to warn about its dangers.

Douthat then offers three examples experimental style: magical thinking, experimenting with psychedelics, and pantheistic art that blurs spiritual traditions. And he continues:

For the stringent materialist, everything I’ve just described is reasonable as long as it's understood to be playacting, experience hunting, artistic experimentation. Only when it becomes serious does it offend against rationality.

However, stringent materialism is itself a weird late-modern superstition, and the kind of experimentation I’m describing is actually far more rational than a life lived as though the universe is random and indifferent and human beings are gene-transmission machines with an illusion of self-consciousness.

So... put me in the camp of irrational believers in stringent materialism. And... by what authority does Mr. Douthat get to declare spiritual experimentation or superstition is "far more rational than life lived as though the universe is random, etc." Superstition is superstition; irrational is irrational. What criteria are Mr. Douthat using for his "far more rational" judgment. Are they utilitarian?... as in "X diminishes or enhances the well being of humans more than Y"? He should explicitly state them.