reflecting on the famous photograph of the earth rising over the moon he took during the Apollo 8 mission:
You have to remember we brought back a picture of the Earth as it is from 240,000 miles away. And the fact is, it gives you a different perspective of the Earth when you see it as three-dimensional between the sun and the moon, and you begin to realize how small and how significant the body is. When I put my thumb up to the window I could completely hide it, and then I realized that behind my thumb that I'm hiding this Earth, and there are about 6 billion people that are all striving to live there.
You have to really kind of think about our own existence here in the universe. You realize that people often say, 'I hope to go to heaven when I die.' In reality, if you think about it, you go to heaven when you're born.
You arrive on a planet that has the proper mass, has the gravity to contain water and an atmosphere, which are the very essentials for life. And you arrive on this planet that's orbiting a star just at the right distance — not too far to be too cold, or too close to be too hot — and just at the right distance to absorb that star's energy and then, with that energy, cause life to evolve here in the first place.
In reality, you know, God has really given us a stage, just looking at where we were around the moon, a stage on which we perform. And how that play turns out is up to us, I guess.