In truth, man is a trilogy, that is, he is composed of three parts.
The first and most important part is the spiritual soul itself, then comes the ethereal body in which the soul resides, and finally the dense material body that contains the other two parts.
The first part concerns the spiritual soul that each of us truly is, for we are not the material body with which we wrongly identify.
The soul is in reality a tiny fragment of God, an integral part of His divine person. Because God is unborn and immortal, the same is true for the soul, which is also unborn and immortal. Since God has life within Him, He has given the soul life within itself. The soul is in reality a fixed spiritual spark, which composes the radiance that emanates from the spiritual body of God from which it originates. This is why the Lord gave it a body, so that it could move easily. Our true spiritual identity is precisely that of an immortal spirit soul.
In the spiritual universe, the soul has obtained from God an eternal spirit body, while in the material universe, it obtains a body of dense matter, which has a limited lifespan.
The second part is none other than the ethereal body in which the soul is enclosed. In reality, the ethereal body has a dual molecular structure, because it must contain a spirit soul and find itself within a material body without this posing any particular problem. Furthermore, the ethereal body offers the soul great ease in controlling its two bodies. Upon the death or temporary end of the incarnate spiritual soul's existence, it is the ethereal body that transports the soul, through the intermediary of celestial beings, servants of God, into the womb of a new mother, so that the latter may give it a new material body.
The third part concerns the dense material body, which is actually a mass of inert material elements. That is to say, the material body is a dead mass, without autonomous life.
In reality, the material body owes its life to the soul, which, omnipresent within it and through its vital force, activates the material body and gives it life. It is the soul, for example, that allows the body to grow, transform, and develop.
When God decides to transfer a soul from one body to another, He asks the celestial beings to take care of it. The latter take the soul and place it within the sperm, which the father releases into his partner's womb. It is through the presence of the soul within that the sperm will come to life and move toward the egg, which the mother will release. From then on, the union of the sperm and the egg will give birth to an egg in which a soul already resides, since the latter arrived there through the father's semen.