This passage of scripture that Peter gives us is so valuable. There's so much in these two verses. First he tells us that we need to abstain from fleshly lusts. We know exactly what he is talking about here - there's probably some kind of "fleshly lust" that we each struggle with. He warns us that these things are going to war against our soul. Think about it like this; Why are we afraid of playing with something like fire? Well, that's easy - because of the damage that it can do to our physical bodies. Well, sin has the same effect on our soul - So why don't seem to be as cautious of it?
In the second part of this passage, Peter encourages us to have an honorable character. It's so important that we are always displaying Christ in the things that we do. Our goal needs to be that other people will see/glorify God when they see our works. In order for that to happen, we must always be making sure we're conducting ourselves in a Christ-Like manner.
As we live before the world, let us be honorable and abstain from fleshly lusts.