"When I did 2 hits of acid, I had the exact opposite experience of seeing God. The fact that such a tiny amount of a mere chemical could effect my "soul" so profoundly was proof positive that the soul is completely material."Your so-called "soul" may in fact be "completely material", but I don't think what you describe above proves it.
There was a famous mystic who once said something like, "when you put a lit match to cotton, it is not the fire that burns the cotton, but God."
Relating it back to your account, how can you know if it was in fact the chemical that changed your consciousness and not the grace of God (or gods, or the devil, some alient, or the program/programmer running your virtual reality, etc).
There could be some cause that caused you to both take the chemical and to have the experience. Or they could be caused by two independent things, with the experiences just happening to succeed one another in time (see Hume's critique of causality).
Finally, I'm not a physicist, but from what I've read, even physicists now have a lot of trouble defining "matter" as such. I don't think they even use the term much at all anymore. And, whatever reality happens to be, it might be infinitely divisible, and ultimately not completely understandable or knowable as far as science is concerned. At the very least, science now does not have a full understanding of it, and to say that science will one day have such a full understanding is merely an expression of faith.