It's Debatable - Positive Thinking & Christianity

I am a Christian and my faith is my lifeline. As I learn on my Journey to Legacy I am amazed to see that there are some Christians who find issue with the idea of positive thinking. Somehow there's are argument that thinking positively diminishes one's believing in or trusting God. I won't get into debate on this opinion but am using this opportunity to begin a new category of blog posts called "It's Debatable" in which I will present my thoughts on different issues that spark debate relevant to Journey to Legacy. For this topic, my thoughts are best expressed  in the following Bible verse which is one that I use often for encouragement:

Philippians 4:8 (KJV) 
Finally, brethren, whatsoever things are true, whatsoever things are honest, whatsoever things are just, whatsoever things are pure, whatsoever things are lovely, whatsoever things are of good report; if there be any virtue, and if there be any praise, think on these things.