The theme or message that can be explained to Noah from the final two stanzas of the poem is:
Even after we're gone, our lives can still help others, and the things we do and leave behind can be seen in small ways everywhere, if people are open to noticing them.
This interpretation highlights the idea that the impact of a person's life continues even after they are no longer physically present, suggesting that their essence or influence can still be found and appreciated by those who seek it out. The lines emphasize encouragement and persistence in seeking out this connection, reinforcing the notion that the meaningful aspects of a person can be discovered in various forms.