When speaking of reincarnation we are speaking of a person transmigrating from one form of life to another form of life.
Obviously, a physical body cannot move into another physical body. So it means that after the death of one body there is something that continues to exist and it is not the material body.
At death, the person leaves the body, the body starts to decay and everybody who was relating to that person who was in that body, starts crying and gets very unhappy. Why? Because the person they were relating to has left.
To understand the science of transmigration of the soul means understanding that the person or living being who was in that body has left that body and if they are not purified spiritually, will now enter into another gross material body.
From the above brief explanation we can understand that the living being is the soul, temporarily encased within a material body.
Anyone can understand that consciousness is spread all over the body. We are all conscious of the pains and pleasures of the body in part or as a whole. What pleasures and pains each of us experiences is unknown to another. Therefore, each and every body is the embodiment of an individual soul, and the symptom of the soul's presence is perceived as individual consciousness.
Living entities in lower species of life exhibit less consciousness that those in the highest form of life, the human, which exhibits greater consciousness.
The point being that when the body dies, you do not die. It's like a suit of clothes. When your clothes become old and torn you throw them away, but that doesn't mean that you no longer exist. In the Bible it says that the material body is like a house that the soul or person temporarily resides in.
With regard to belief or disbelief, it's not difficult to understand. The body is constantly changing. All the cells die, the molecules change and presto, you have a new body. It has been documented that every seven years all the cells in the body become new ones. So the body you had when you were three years old is long gone but you are not.
This means that the material particles that are making up your body now are not the same material particles that made it up previously. But, there is a substance, which has continuity and continues to exist even though your body kept changing.
If you look at a picture of yourself 20 or 30 years ago you can understand that although that body in the picture is not the body you are wearing now, you still exist. This is evidence of transmigration: from baby body to boyhood body to youth body to man body to middle age body to old age body and so on.
Then there's the confusion that we are the mind. But the mind is actually a subtle material body. In the same way that the material body is always changing, so is the mind. And who is the person watching the mind change? You!
Did you ever try to control you mind? Did you ever say, "I changed my mind"? What happened? Total frustration, that's what happened. What do you do when your mind is driving you crazy? You try, to no avail, to control it. Or, you try to make your mind blank and think about nothing. Riiiiight!
The point here is whether you try to make your mind blank, or you try to move you mind in one direction or another, or you can or you cannot; it is something other than the mind that is trying to do all of this. And that is you, the soul that is the witness of the mind.
So then, how does the mind figure in the process of the transmigration of the soul? The soul leaves the gross material body but is still covered by the subtle material body, like the material desires and the recordings on the mind of the impressions, which are made on the mind from past experiences in the previous body.
For example, you have many central experiences. You see a bird and by your eyes seeing that bird, that leaves an impression on your mind of the form of the bird. All of these forms and all of these subtle images and material desires are still covering the soul. In other words it is the subtle body, the material mind that is still covering the soul. When the soul leaves the gross body, this covering makes it so that the soul takes on another gross material body. The subtle material body, the mind, is a nucleus around which the gross material body develops.
So, if the mind is still in existence when the soul leaves the body and all that stored information is not erased and the soul is still covered by the subtle body, which is the material mind, that means that I should be able to remember my past lives because I still have the same mind or that information is still there? Yet, I cannot remember my past lives. Does that mean there were no past lives?
Well, despite not remembering my birth in this lifetime I still know that I was born. I can't remember leaving the womb nor can I remember being in the womb but I know that I was. It is nature's arrangement that our memories are imperfect.
Some people spend all kinds of money to go back to remember past lives. What's the value? There are 8,400,000 species of life in the material world of varying bodies. What value would it be to know what kind of animal or flower or microbial creature you were? An intelligent person will not be enamored with the mysticism of it all but rather, will seek a solution to stopping the process.
Actually many people do not recognize that it is a problem for the living entity who is eternal by nature, to be bound up in the temporary, finite, material dimension, having to undergo repeated birth, diseases, old age and death. As such, they fail to see this as a suffering condition.
To put is another way, the activities one cultivates in his or her lifetime has a definite bearing on the life they take on next time around. For example, a dog eats, sleeps, mates and defends. Sounds familiar doesn't it? What sets us apart from the dog is the cultivation of consciousness. It means being in the world but not of the world.
That means turning to God and using the world for His pleasure. To put it another way, the point is to develop an attachment for God, or God consciousness. If you're attached to God and do everything for Him, you'll automatically be detached from the world. Then the question of coming back to the material world is then non-existent. And since your consciousness will be directed toward God you will go to Him when you leave your body.
It is said that we all began in God's spiritual world. Due to our envy of God's enjoyment He sends us to the material world, which is full of suffering and false enjoyment, to fulfill our desires to act like God and try to enjoy our senses to the fullest. Even though we are constantly unfulfilled, depressed and miserable, we try harder to enjoy our senses and create more and more frustration.
True happiness is found when we link back up with Him and affords us the opportunity to not have to come back to the material world when we leave our bodies.