The riddle of life and death

You cannot have life without death and you cannot have death without life. Destruction begets creation and creation begets destruction.
Each cell's death precedes another's birth, each new thought ushers out an old one, and each life has a beginning and an end.
With change there is death. Without change there is no life. For life is change. And therefore, life is death.
Yet, and yet, throughout all of this, as you pass through every fire, is you, glorious you. Thoughts come and go, your cells are born and die again and again, and yet you are, the core of you is. Mind changes, body dies, sprit remains, constantly recreating.
Of course everything changes, and the part of you that is changing is constantly being born and dying, but you bestride like a collosus.