Parasite: An organism that grows, feeds, and is sheltered on or in a different organism while contributing nothing to the survival of its host.
This sounds awfully familiar. In fact, it sounds just like what humans do to all other animals. We live off of the Earth, but rarely contribute to making her better. Watch as we slowly, but surely, rid the Earth of her beautiful creatures, and plants. Watch as she tries to produce more, but can not because we humans are consuming everything Nature is trying to bring forth. A handful of people try to give back to the Earth, but most of these people are not Christian, and therefore do not constitute as a majority. The majority drinks back what Earth has to offer, and does not respect her. We are much like a louse. We suck the blood from our host, and just cause a general grievance to her.