It may be hard for an egg to turn into a bird: it would be a jolly sight harder for it to learn 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
There are a lot of things that a person can become in this life. Unfortunately none of those things happens without a lot of change and a lot of work. For us very often this means that we must do the work and make the change happen ourselves. Nobody else is going to do it for us.
The gem of truth I like in this quote is that we either have to do something or by default we won't achieve what we want. Sloth by its very nature drives us to become less than what we are, and that in and of itself is (or should be) enough to convince me to be a better person.