[voice]
That would depend on whether or not you exist in a world where souls exist. And even then, many things in the world are not physical, but are still bound by their own laws.
It may differ then, depending on what is common within your own world. Perhaps there is a soul for everybody, because the body itself is made up of various energies. Or perhaps the soul is merely a reaction of the brain to those energies.
There are too many variables there to create a definite argument that there is indeed a purpose to the soul, or that there is not one.
[She asks too many questions as if one person should know the answers when the questions she asks are ones that one person cannot answer alone. There will never be one answer. Such a child.]
What does life do for a person, you may ask as well. It is measured by the individual.