From what I understand, psychedelics facilitate the connection of different areas of the brain which don’t ordinarily speak to each other. This can be a profoundly spiritual experience, as it tends to be for me, but it will more or less FORCE you to deal with any issues you might have, which can be a terrifying experience for some people.
My own advice is always to make sure you do it in a controlled environment where you can adjust the level of stimulation (lights, music, etc) at will, and make sure you have an experienced friend to take care of you.