I'm going to go at this from a rather round about way, so prepare for your coma now
My father was an artist. From the time I was small, I would sit in his studio and watch him paint and he would explain to me why one uses certain colours to get certain effects. I didn't understand that he was actually
teaching me to 'see' on a different level. We tend to take our senses for granted in that they come 'fully informed'. I believe for some they do, but not for many. Anyway, we used to take this trip every year and stop at this cafe in a canyon. There was this rock cliff and my father and I would marvel at all the colours on the the rock face. Later in life, whenever I made the trip with someone else and we stopped there, the inevitable reply when I explained why I was staring at this cliff-face was " It's just grey with some green plants on it". The people never saw the blues, mauve, deep purples, reds, umbers, the many shades of green etc., etc. . Until. One time I made the trip with someone who was also an artist. When I came out of the cafe they were just staring at that cliff face with awe and remarked on all the colours.
Same with music. My family 'taught' me how to listen to music. I don't think very many people really like opera or classical music starting in the 'Romantic' period when they first hear it. But if they are taught what to listen for, one day it just 'clicks' and it's a whole new world ( mind, I'm just speaking for myself, I'm not saying it's the same for anyone else).
So, when I first took hallucinogens , do you know what 'altered'? Nothing. I found that I could already 'see' the things other people were seeing. ( O.K., I admit finding out that lettuce is still breathing when on the plate was a revelation

or just a drug badly cut with something else). Every drug I tried ( Yes, I was a , shall we say, 'adventurous' youth? was the same - boring and actually, I found it disrupted the 'natural' flow of my senses and was an irritant.
Well, that's just writing about 'perception', so perhaps it doesn't apply?
What about traveling about the much heard of but by many never experienced 'Astral'. Well, I've experienced or tried just about every thing that supposedly can induce an 'altered state' and...nada. Again, perhaps it's just my physiology.
Pain is aversive to the human body - the body doesn't like it. Naturally, there is a small store of endorphins and ekephalins to help counteract pain. But prolonged, debilitating pain causes the body to habituate to it and stops sending out the nice stuff. I wonder how many women here found the pain of giving birth 'transcendent' after hours of labour? It's one thing to get a tat., quite another to give birth or have surgery or break bones.
There is another thing to consider about the 'religious' use of pain for an altered state. Before the advent of antibiotics, sepsis could kill. Mortifying the flesh or seeking a 'transcendent' state had a small disclaimer attached - the altered state may be death. I'm not using hyperbole. So if one flogged themselves for religious purposes, that had the possibility inherent in it of actually dying for what the person believed in. Now
that's 'faith'
The second part of this is the deity thing. I've noticed that some of the same people that claim to hob-nob with their deities on an ongoing basis may also engage in 'state altering' behavior.
Why? If one can have a chin-wag with their deity at any time, why bother?
Is it to try and access the deities 'realm'? Serious question.
So you see the genesis of my question. I believe we come fully equipped to experience all those things which are within reach given the boundaries of our human form ( for instance, we cannot see in the infra-red scale - doesn't mean it isn't there).
I think we just need to , hmmm, educate? ourselves to the maximum , of trying to find out just how inclusive this package we call 'human' ...is. I'm also having trouble believing that people can transcend their 'humanness' . But the biggest question to me is :
WHY would anyone WANT to given how wonderful and acutely attuned to our environment we are given the millions of years that have gone into the creation of what we call 'human'.
Marto