That is why one might recommend psychedelic experiences: you are likely to come back with a conviction that your soul existed for eternity before your birth and will exist for eternity after as well.
I think this is highly dependent on what your beliefs are pre-trip and how you define what makes you you. I've had many psychedelic experiences and while I often feel greater connection to living things around me, I've never been left with the feeling that my "soul" or anything I'd define as me will exist when I'm gone.
This is congruent with the sense that my ‘soul’ is a local aspect of the dynamics that have been playing out in the universe and will continue after my death. I am a little piece of the dance, for a while.