Philippians 4:8-9 (NIV)
Finally, brothers, whatever is true, whatever is noble, whatever is right, whatever is pure, whatever is lovely, whatever is admirable--if anything is excellent or praiseworthy--think about such things. Whatever you have learned or received or heard from me, or seen in me--put it into practice. And the God of peace will be with you.
I've been told I have a one track mind. I believe that we all do. As amazed as I am by women who can seemingly carry on multiple conversations at the same time and still hear her baby cry in the background, I believe all of us can only think about one thing at a time. (Apparently women can just switch back and forth more easily!) This is actually a good thing for us. It means that whenever we are tempted with bad thoughts, we can simply replace them with good ones. Paul gives some general guidelines for the types of thoughts we are to have. Then he goes one step further, he says that after you have thought about such good things such as he has personally demonstrated, we should put them into practice. What is the result? The God of peace will be with you.
2 Corinthians 10:5 (NIV)
We demolish arguments and every pretension that sets itself up against the knowledge of God, and we take captive every thought to make it obedient to Christ.