On the most global scale this story is about human values namely friendship and sacrifice. Sue and Johnsy were living in reduced circumstances, but still they were rich in soul due to their constant love and support towards each other without even hesitation to sacrifice their own life.

Another theme the author focuses on is a sacrifice. We saw how Mr. Behrman gave his life to help Johnsy. He made the greatest sacrifice anybody could make.  

Within the story the author tries to teach us not to lose hope and not to abandon yourself to despair. He wants to point out in particular that only a strong and confident person can survive in difficult life situations.