The main theme is Death. From the beginning to the last line, the poem is about dying. It gives us a look at the issue from a bunch of different angles. It deals with death across different times, and from all around the world. It speaks about how it makes us feel, and how it is related to spirituality and/or religion, history and how it helps nature. Mostly the purpose is to remind you that you will die, but that it's not something to be afraid of. I hope this helps you!
