It is still better than the lowest for the study, the sample size of one: "Well this is what I experienced". Yet here I go.
I have always been a materialist, and I've also never done drugs (I'm in my 50s). A few years back I bought some lysergamides and tryptamines online, and over the course of two years did between 20 and 30 experiments, though never of high doses (at most, 200 ug LSD). I found the LSD to be quite interesting, but not the least bit spiritual.
The first time I did 4-aco-dmt (aka psilacetin), a very close relative to psilocybin, was a different story. It was a 25mg-ish dose, taken orally. It was far more intense, and dreamy, and soporific than LSD (for me), and it gave me a glimpse of what something I was hoping to experience: spirituality. It was unfortunately fleeting -- I was lost in "the light" but then became aware that I was actually lying in a bed, and without thinking, opened my eyes for a moment to confirm. I closed my eyes but that moment in the light was gone for good.
I've tried a few more times, but it has mostly been uncomfortable and confusing way to spend a couple hours.
Anyway, I came away from those experiments even more of a materialist than I was before. If a hundred micrograms or a few milligrams of small molecule can so disrupt one's mind, if it can profoundly change your perceptions, if it can induce a feeling of being in a divine presence, it confirmed to me that the brain is all just chemistry.