I had what I thought was a spiritual experience as a churchgoing young person. Maybe I really did, I don’t know. It felt real at the time: what they call being “born again,” but long, long before it was fashionable or a catch phrase (or associated with a certain segment of the culture). Now I regard it as having been an emotional high brought on by overstimulation in a setting calculated to produce that effect. In that respect it was probably not too different from what some people feel at rock concerts or in the presence of a celebrity they admire.
And no, it didn’t stick, although I went on for the next few years as if it had, before finally chucking the whole business.
I’ve also had a few drug experiences (again, long ago) that felt revelatory but not spiritual. The memory of them lasted, but not any other effects.
However, I do believe that spiritual experiences are possible, both drug-induced and sober, and both sought-after and spontaneous, and I do think they can bring about permanent change in some people.
I read a fascinating article years ago in Tricycle magazine that explored the authenticity of drug-related “enlightenment” experiences. The most compelling statements (in my opinion) came from people who had used hallucinogenic drugs in San Francisco in the sixties and then sought out and joined a Zen practice (with Suzuki-roshi at SFZC) to try to find out what had happened to them and to sustain it. There were those among the interviewees who said that they didn’t believe there was any significant difference between what came out of one deeply effective psychedelic experience and thirty years of meditation practice.
Naturally others said that one was genuine and the other was artificial, and they scorned the latter, but they couldn’t support an argument that the quality of enlightenment was different. I thought it was basically the difference between earning a million dollars through hard work and winning it in the lottery: you may feel differently about the process, but a million dollars is a million dollars.