"When He said 'Be perfect,' He meant it. He meant that we must go in for the full treatment. It is hard; but the sort of compromise we are all hankering after is harder - in fact, it is impossible. It may be hard for an egg to turn into a bird: it would be a jolly sight harder for it to fly while remaining an egg. We are like eggs at present. And you cannot go on indefinitely being just an ordinary, decent egg. We must be hatched or go bad."
-C.S. Lewis Mere Christianity
[disclosure: eggs are repulsive to me. But this analogy isn't repulsive.]