This short thought comes from Ryan Francis, shepherd of the USC GOC Bible study, on February 7, 2014 (paraphrased):
Here’s an illustration of eternity. Let’s say that we have a bird. Our little friend goes to Santa Monica beach and picks up one grain of sand and flies to the moon, drops it off, and comes back. When he arrives, he picks up another grain of sand, flies to the moon, and comes back. He does this until all the sand on the beach is gone. Then he moves down the coast, around South America, and up the East Coast. He does this until every grain of sand in the world is gone. Then he picks up a drop of water from the ocean, flips to the moon, drops it, and comes back. He does this until all the water in the ocean is gone. When he is done, eternity is just beginning.
If I would remember this when I am tempted to sin, I imagine the fight against it would be much easier. Who trades temporary pleasure for overwhelming eternal pleasure? Matthew 6:19-20; Hebrews 11:16, 24-26.