I read all of Michael Newton's books on past life regression, and I had a past life regression session. I have other books that I have read on the soul.
I believe that we have what is called a human personality, and we also have a soul, which is made up of energy.
In my college science book, the first sentence is, "Energy never dies." So that is a scientific fact that we have a soul.
Michael Newton is a psychiatrist that does hypnosis, which is another scientific fact (meaning it can be proven to be true). Over 7 thousand case studies of people from all over the world, he came to the conclusion that each of us has a soul.
His books explain that when you are developing as a fetus, in the spirit world, you, in spirit, and your spirit guides are helping you pick the earth body and the earth personality in which you , your spirit will be able to learn and gain the most knowledge to then progress in the spirit world.
It's your soul that is always trying to mesh with your personality. When you are happy, and doing something that you most enjoy, is when your soul and personality is connected.
I hope this helps. Reading the books, and hopefully having a session would benefit you greatly.