Since the day I tried MDMA, I have also experimented with Psilocybin (Magic Mushrooms) and LSD. And even though the effect is very different than MDMA, I can see where people might get a feeling of the experience being spiritual on hallucinogens. During my first LSD experience (it was in nature), I had a feeling of being connected to trees and grass. No idea what to do with this...
I spent what seemed like hours, but was actually the length of The Beatles Abby Road, talking with a tree at the banks of a lake in Michigan. I also ran my fingers through the water of the lake while sitting beside the tree. The next day I sat at the base of that same tree, baffled by the fact that the water was at least 20 yards away. LSD is a powerful thing, be careful and enjoy.