“A Psalm of Life” is a poem written by American writer Henry Wadsworth Longfellow, often subtitled “What the Heart of the Young Man Said to the Psalmist”

Tell me not, in mournful numbers, 
   Life is but an empty dream! 
For the soul is dead that slumbers, 
   And things are not what they seem. 

Life is real! Life is earnest! 
   And the grave is not its goal; 
Dust thou art, to dust returnest, 
   Was not spoken of the soul.