Look up into the night’s sky, and you might see one of the other planets in our solar system blinking back at you. But what you are actually seeing is the sun’s light reflecting off the surface of a heavenly body, much like how the moon’s light is merely a reflection and how the shadow of the earth cuts into that brightness.
Without a sun, planets live in darkness, with one exception. Earth is the only planet (that we know of) that generates its own light.
Think about that for a minute and ask yourself a couple of questions.
Do I do a good job of reflecting God’s light or do I let the world darken it out in shadow? And do I generate my own light?