The Earth is our home, and usually we tend to think of it as an inanimate object, but it is actually a living, breathing entity full of life and wonder. The phrase "mother Earth" is not just a catchy phrase, but a perspective that looks at the place where we live, work, play, etc. with respect. It is this attitude of looking at the world in a loving, positive and uplifting manner that directs us to treat the place we call home with care.
The efforts of individuals to better the planet, including the creation and observance of "Earth Day" have led to a greater awareness of the need to properly care for the environment and the people who live in it. It is almost cliche and common sense to admonish one to take care of the planet nowadays, due to the greater awareness we have now of the need to do so. Al Gore's cause and the causes of countless others strengthens this awareness daily. The same way one cleans and maintains one's house, apartment or other dwelling, should be the same way the world population maintains the planet.
I remember a science fiction movie starring Charlie Sheen that ended with the admonishment that if we didn't take care of our own planet, then others would step in to take it over. That movie may not have been far off the mark in relation to the logic that with all of the millions of stars, planets and galaxies in the universe ours is probably not the only one inhabited with life. Also the widely witnessed phenomena of unexplained lights in the Nevada sky, and unexplained phenomena across the globe support this notion that we are not alone.
If we were to be visited by extra-terrestrials, what kind of planet would we want to host them in? I would think that we would want it to be clean, respectable and suitable for guests. Moreover, if the world's populace got together to make the Earth a better place to live, less time would be focused on international squabbles, making for a better living situation for all.
But largely, the Earth was given to man by God, and meant for him to enjoy and treat with respect. Adam and Eve were given the garden of Eden, and subsequently forced out, after they disobeyed a commandment by God in regards to a living thing that existed in it. We can view our relationship to Earth the same way, and learn to obey the laws that govern nature, to our own benefit, creating a harmonious atmosphere with which to live and play.