Question

Which lines in the poem indicate its theme? A Shadow by Henry Wadsworth Longfellow I said unto myself, if I were dead, What would befall these children? What would be Their fate, who now are looking up to me For help and furtherance? Their lives, I said, Would be a volume wherein I have read But the first chapters, and no longer see To read the rest of their dear history, So full of beauty and so full of dread. Be comforted; the world is very old, And generations pass, as they have passed, A troop of shadows moving with the sun; Thousands of times has the old tale been told; The world belongs to those who come the last, They will find hope and strength as we have done.

Answer 1

 The world belongs to those who come the last, They will find hope and strength as we have done. 
I'm pretty sure that is your theme. The way a theme was defined for me is as a universal truth. It's something the whole world can agree on. Or, the theme of a party is something that can be recognized and agreed upon by the guests.