Are you a Christian? You then probably don't believe in souls unless you are a new age believer.
Many spiritual authorities have spoken about souls. I would not buy the logic that I as a Hindu believing in soul tradition have one, while you as a Christian, who does not believe, don't have it. One thing is for sure: if I have a soul, you do and if you don't, I don't either. Are we not just lost in spiritual translation?
A spiritual guru gives a discourse on soul. Many don't understand and ignore it. Few will believe without understanding. One will dare to experience it. I happen to be one.
If you watch the Netflix original Altered Carbon, and read this, you will probably discern the nature of soul without experiencing it firsthand, though ultimately all will.
In the dystopian future of Altered Carbon, human body is simply known as a sleeve. It is just a laboratory synthesized body. Just flesh. Nothing much. All the information that the brain of a sleeve generates or the experience that it stores while it is alive, can be decanted into a disc-shaped device called stack, implanted in the vertebrae at the back of your neck. When it dies, all those information that were stored in the stack, can be reimplanted into a new sleeve.
Say for example, sleeve A is an actor. When the actor dies, the stack has all the information of that actor. After sleeve A dies, that stack is transferred into sleeve B, who is a businessman. When the businessman dies, the stack now has the information of both the actor and the businessman. Now it is put into a new sleeve C, who is a carpenter. When the carpenter dies, the stack then has the information of the actor, the businessman and the carpenter. Let's say sleeve D is a doctor and sleeve E is an engineer. Though this stack has now managed to have so much of information in store even if it is put into a new sleeve, ordinarily the function of that sleeve will not necessarily be the manifestation of the entire information stored in it and will have limited functionality. So, despite having so much of information in the stack the sleeve may just live a life as a teacher and not be able to translate the information in the crevices of the stack to act like an engineer or a doctor at the time of need. But the question is: is it at all possible? The answer is yes.
Now let us for a minute assume that sleeve is equal to a body and stack is equal to a soul. Meaning Body: Soul:: Sleeve: Stack.
Contrary to the fictional placement of a stack in the vertebra at the back of the neck, it is not an easy task to define the position of a soul in a human body. It can be diffusely integrated into the entire construct of a body in the form of conscious energy. With meditation one may be able to reduce it back to its innate physiological nature that in its state of ultimate purity is capable of emanating light. Else, at the time of death, depending upon the level of your spiritual attainment, you may wake up in subtler physical forms in this plane, or other ethereal planes and attain various degrees of soul realization.
Soul realization is possible prior to death by means of meditation or various forms of yoga. Soul realization may not directly translate into absolute enlightenment, if there is any experience of such nature, but it is certainly one of the steps in the pathway of enlightenment. As someone rightly mentioned, there are degrees of enlightenment. While the distinction between awakening and enlightenment itself is a little murky, I consider the term "degrees of enlightenment" to be a better expression.
If you can comprehend the possibility of stack migration from one sleeve to the other, can you contemplate transmigration then?
Transmigration, meaning migration of soul from one body to the other. In my earlier life, I was a musician. In this life I am a neurosurgeon. In the other life, I am going to become a warrior. My soul is keeping the memory of my past, present and the gamut of future experiences too. So if I attain soul realization in this life means, that I will be able to operate not only as a neurosurgeon, but I will also be able to play piano like Beethoven or fight a battle like Alexander, in this very life itself. My soul has been moving from one body to the other body in various planes of existence, over various timelines. My soul. It has got everything in reserve.
But then comes the most important realization, probably more important than soul realization itself. Is our body merely a sleeve? The answer is no.
If and when soul gets access into the body, is yet another debate. But for all practical purposes, let us assume that soul enters the body at the time of fertilization. So in my making there are two important components: the zygote from my parents, and the soul that enters into it: the sum of which is me. I am a function of my soul, my father's gene and my mother's gene. My father's gene is a function of his soul and the genes of my paternal grandparents. My mother's gene is a function of her soul and the genes of my maternal grandparents. This very well explains why a body is not just the function of a soul.
A laboratory synthesized sleeve may apparently appear inferior to the stack but a naturally born human body is not. This is why the eastern tradition puts so much emphasis into yoga, meaning yoking of body and mind; mind here being the direct function of a soul.
The choice between a stack and a soul is also the choice between the Christ and the beast. It is for you to realize who offers you a stack and who offers you a soul.