Hypothetically speaking- Suppose I leave this body this very minute, my body still exists but is without a life. I cannot function in a dead body. All my belongings like my body, my family, my job, my house are still here but I am not here to use them, so who is this- I ? who vanished away leaving me a dead body 

The answer would be the I- the soul or the spirit  residing in this body.  Indeed! I am a soul is not something any of us remember any time- right? Hardly any of us realize it in everyday life. We simply live by the days fulfilling needs and essential requirements of the body. We don't see this subtle energy which is in real our identity so we call ourselves a body and  believe all of the possessions and relations we hold are due to this body. This wrongful image I carry all my life while living in this body. I work timelessly for all my belongings but never take them with me. Most of us know and understand that we slog in vain yet we do what we do lifelong. 

One main and most important detail- that I am a soul is the only thing I don't take care of,rest others I hold very tight, cling on to it and never let it go!