Most people believe that death takes place when the heart stops beating; but this does not mean that the person has died, because his subtle mind may still remain in his body. Death occurs when the subtle consciousness finally leaves the body to go to the next life. Our body is like a guesthouse and our mind like the guest; when we die our mind has to leave this body and enter the body of our next rebirth, like a guest leaving one guesthouse and travelling to another.
The mind is neither physical, nor a by-product of purely physical processes, but is a formless continuum that is a separate entity from the body. When the body disintegrates at death the mind does not cease. Although our superficial conscious mind ceases, it does so by dissolving into a deeper level of consciousness, the very subtle mind; and the continuum of the very subtle mind has no beginning and no end.