I woke up this morning thinking about this question of self. The problem for most of us, at least in the West, is that we see ourselves as substantial and enduring entities. I am the same person I have always been. I may have changed physically, and many of my ideas, my likes and dislikes, even my values may have changed, but I am still the same person I always was. This is the common perception.
This perception is reinforced by the Christian idea of a soul. In some way my soul is me. It was directly created by God at the moment of conception. When I die the soul will leave the body and go to Hell, Purgatory, or Heaven where it will wait until the Last Day and the General Resurrection, when the bodies of all who have died will rise and be united with their souls. Then those in Purgatory will join those in Heaven for an eternity of blissful happiness while those in Hell will remain there for ever.
When one looks carefully at this worldview a number of questions emerge. Is the soul substantial, i.e. the essence of a human person; that which makes it what it is? This is the Christian position, one which is based on Plato and Aristotle. It is dualistic, the soul is separable from the body and has an independent existence after death, at least for a time, until the General Resurrection. The earlier New Testament tradition, on the other hand, is not dualistic. The person is a living body. If there is to be life after death it can only be for a risen body.
Of these I prefer the NT version. One can imagine oneself as a mind within a body, detachable from it, at least notionally. But more generally our experience is that body and mind are two aspects of the same thing. Each affects the other profoundly. The idea of a detached mind, or soul, raises many problems. How can a soul, a mind, a purely spiritual entity have feelings, emotions and moods?