The second half of this message vanished.  Here's the jist of it.

How far do we allow our minds to wander? 

The apostle Peter wants our minds too ponder the truth of our faith with every bit of concentrated effort. 

What is a specific way Peter urges us to make every effort?

A fight against thoughts we know are greedy or immoral, Peter says is critical.  We will at some point encounter teachers who will subtly encourage you to allow sinful, lustful thoughts to linger in your mind.  Jesus died for you so it is ok.  He'll forgive you.  It is easy to forget that we were cleansed completely from our old sins and now to not make any, none, no room at all. 

We are called to be holy in our thinking.  If we lose that battle in our mind, we will lose the battle in our hearts and once we lose our hearts, we could return to the vomit like a dog or the mud like a pig.  It would be better if we had never known the truth.  2 Peter 2

Thank Jesus for his salvation and fight, fight, fight for clean thinking.