2 Cor. 10:5 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.
In meditating on this passage today, I realized that I have misunderstood what is being said in this verse. I have thought of this capturing of the thoughts as being a sort of filter. That our thoughts should be captivated by Christ BEFORE they enter our minds. While I don't want to downplay the importance of being transformed in our thoughts to think with the mind of Christ (as Paul puts it - 1 Cor. 2:16), we also live with something that Jesus never did - namely a sin nature. It is impossible for us to be completely transformed in our thought life before being completely free of the sin nature. This will come someday, but for now we must learn what it means to live out the battle between the Spirit and the flesh.
Instead, this verse demands that we capture every thought and "make it obedient to Christ." In order for something to be made captive, it must first be free. How those thoughts get into our mind is somewhat irrelevant. Whether it was the world, the flesh, or the devil caused that thought to be there is not important. All three are warring for supremecy in our minds. But we have a King who has purchased us. It is not our perrogative to allow those thoughts to be running loose. Therefore we are to take them captive. This practically means that we must become disciplined in our minds. To allow thoughts to run loose without examining them is to disobey this passage.
Ok, so much for the theory - now, what does this look like? For me and I think most people, we think about a lot of different things on any given day. Many of them good and God glorifying and many of them sinful, some of them are somewhat neutral (i.e. "Should I wear a green, red, or blue shirt", etc.). All three of these categories need to be examined.

• In the thoughts that I think are God glorifying, am I tainting those thoughts with my sin nature (am I thinking wrongly of who God is as revealed by His Word)?
• In the thoughts that are sinful, they must be captured, but it doesn't end there. C.S. Lewis said, "What springs from myself and not from God is evil: It is a perversion of something of God's." All sinful thoughts should first be killed. Next, identifying how we are wrongly thinking and seeing God's thoughts on the matter allows us to "redeem" these thoughts. Making these evil thoughts obedient to Christ often includes correcting the wrong orientation of our fleshly minds. Example: Suppose I find myself coveting a nicer car. Clearly I am stepping out of the boundries defined by Scripture by coveting. My thoughts are sinful. Instead of allowing these thoughts to run, they must be taken captive and made obedient to Christ. In this particular case, I might remind myself from God's Word what true blessings are. God has given me so much to be grateful for!
• In the thoughts that we think are neutral, make sure they are! As I looked back on my example of the red, green, and blue shirt - I realized that even there, in my drawer, I have the potential of this neutral decision becoming not so neutral! My green shirt has a Guiness logo on it, so obviously, I must allow wisdom and love be my guides in when to wear this shirt and when to not. The blue and red shirts are both unoffensive so I would conclude that the decision is primarily neutral (I think). In this example I find that even the "neutral" decisions I can make often are not completely neutral and must be examined to see if I have allowed room for sin.