(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.
How do we keep our minds clean? We are to “think” (let our "mind dwell" NASB) (3049) [logizomai] on these kinds of things. Someone, sometime pointed out that modern psychology has “discovered” this truth. Finally. How do you keep something from dominating your mind? By focusing on something else. If I tell you not to think about oranges it does you no good to try to push oranges out of your mind. All it does is reinforce the idea of oranges. If, however, you get an apple and start savoring its nuances and unique tastes the idea of whatever it was is pushed aside.
So fill yourself up with the righteousness of God and the evil will not be able to find room. TV anyone?