These lines of reference to context are from H.W Longfellow’s poem “A Psalm of Life.”
In the sixth stanza of the poem the poet is attempting to convince the reader of what the correct attitude towards the past and the future should be.
By “Trust no future” the poet advises us not to trust our future, however pleasant it may appear now.
It is because we cannot completely be certain of what the future would bring to our life.
What looks very good at this point, may change with time.
Moreover, we may get lax if we are obsessed with our bright future and neglecting our duties at hand.
Instead of dewelling in the past, as we so often do, instead of being nostalgic about it, we should leave it alone.
We can’t go back in the past and change anything.
Hence the only thing we have in our hands in “The Present ” so we should work with dedication and perseverance so that our today becomes worthy to be lived.
Final Answer: Hence in the poem “ A Psalm of Life” by H.W. Longfellow, Poet is defining the correct attitude of his reader towards past and future and ultimately focussing on the fact that greater good can be done only while living and working in the present.