147. Behold this body — a painted image, a mass of heaped up sores, infirm, full of hankering — of which nothing is lasting or stable!
148. Fully worn out is this body, a nest of disease, and fragile. This foul mass breaks up, for death is the end of life.
149. These dove-colored bones are like gourds that lie scattered about in autumn. Having seen them, how can one seek delight?
150. This city (body) is built of bones, plastered with flesh and blood; within are decay and death, pride and jealousy.
151. Even gorgeous royal chariots wear out, and indeed this body too wears out. But the Dhamma of the Good does not age; thus the Good make it known to the good.
From the 'Sermon on the Mount'
Do not lay up for yourselves treasures on earth, where moth and rust destroy and where thieves break in and steal, but lay up for yourselves treasures in heaven, where neither moth nor rust destroys and where thieves do not break in and steal. For where your treasure is, there your heart will be also.
Spirituality is the search for what is beyond birth, death and decay; that is 'what your heart should treasure'. It's no use asking whether anything of that nature exists, from a hypothetical or lounge-chair perspective; you have to engage yourself in the quest for it; that is what it takes to ask the question. It is a question you ask with your life
This can be easily differentiated from a 'naturalistic ethic', as anything in nature is, by definition, subject to birth, decay and death; whereas, in the realization of the 'true identity', one is seeking that which is beyond birth, decay and death.