Essence before existence

Long I saw it for the Earth's hidden meaning
Long as a youth was my search in vain
Now as I approach my last years waning 
My search I must begin again

Pastor John Piper wrote this poem when he was 17.
There is this search that is not futile.
There is this search motivated by a desire not to subject his life to futility.
There is this fear to waste life away.
There is this passion to make his life count.

This is an assumption for this search: there is a purpose that we did not create but given.
Somewhere out there, there seems to be an ultimate, objective and firm reality outside of us,
defining our essence which we should bring our essence into conformity with to find meaning.