A full understanding of life can't be found only by looking at cells and molecules. Conversely, physical existence can't be divorced from the life and structures that coordinate sense perception and experience.
The goal of life is life. Every impulse and thought is a device developed toward that end. Even poetry and art reflect our humanity and are impelled by instincts -- fear and powerlessness, association and love.
The 'Who am I' feeling is just a 20-watt fountain of energy operating in the brain. But this energy doesn't go away at death. One of the axioms of science is that energy never dies; it can't be created or destroyed.