Take the christianity bit a little further; "I" becomes God. At the beginning, followers of God were pure and righteous and as it developed, it became corrupt and stained. And if "I" is God then he is looking at his place in the world today, where morality has ceased to exist and the kingdom he had built crumbled with the progression of thought, science, technology, and the destruction of hope, faithfulness, and love. Further more, if "I" is God, then the final verse implies that human morality will come about again. I believe that this song is about human failure to be as we were intended and through such, God perhaps feels as if He has failed.