Before continuing on in Second Peter, I looked back at the first four verses. The analogy just popped up right in front of me. Here was Peter – that gruff, tough fisherman who is now confronted by a society (Emperor Nero) who wanted to kill Christians. This wasn't just a "kill'em" kind of thing. It was find them, torture them until they babble on and on about how they are not believers, begged not to be killed and then keep going until they die. Nero wanted those early believers to deny that Jesus was their "King" because he wanted to be recognized as their king.
What brought the flour to mind is in verses 3 and 4 where Peter says that what we become is not [more]because of what we generate or create on our own, but because of the power and knowledge that He (Jesus) gives to us. A sack of flour has no power to become bread or pizza dough on it's own. It takes something outside itself to give it the power. Even then, once it is mixed with water, yeast, salt and other ingredients, it does not have the power to stir itself in the bowl.
That sack of flour is just like a rock sitting by the road. It has no power to roll across the road unless someone or something forces it to move – gives it direction and energy.
So it is with our lives as believers or Christ-followers. We get the power from His words. When we take them in (you know, study and think about what He said), then we have power because we have direction. It is not until that happens that we can effectively live.
Look at it this way – a battery has no power unless and until someone gives it the chemicals that cause the reaction to produce electricity.
You can sit there like a sack of flour or a rock, or you can open up and let His words fill your life. It's a decision that you have to make many times, every day.