A: There has long been speculation about the soul—what it is, where it resides, how it is nurtured...but it is a fairly common belief that the soul is the non-material component of a human being, a component that posesses immortality. And this belief is true. Only the details have been missing.
The Urantia Book dispels all doubt as to the soul's origin and purpose. We learn that the soul is the spiritual counterpart of a human being which is born at the moment of the person's first moral choice—usually at about age five. Coincident with the first moral choosing, this occasion also marks the arrival of the indwelling Spirit of God into the mind of a human being. At this time, this brand new entity is created, and its evolution and growth is continued throughout a lifetime by every new choice towards the good, true and beautiful. Rather than something that enters a human from without, the soul is born from within, and is nurtured by continued identification with the indwelling Spirit of God. And at the end of life, it is this entity which survives the death experience and goes on to eternal life .
Please see Jesus' Discourse on the Soul for a far more inspiring explanation than I can give...
Thank you for this important question."