The Christian life is so much more than avoiding negative things. It is primarily about engaging in thoughts and activities that bring honor to God. In Philippians 4:8-9, Paul urges Christians to focus on things that are excellent and praiseworthy. Here are two practical examples of doing this: Two young children are fussing and complaining.
Negative response: "Why can't you two just be quiet! Being noisy and fussy is a distraction to everybody in this house. I don't want to hear any more unpleasantness, and I mean it! Do you understand?!?"
Response that encourages excellence: "God's Word says that we should be thankful for each other. Sarah, Ethan, remember that we talked about things we can be thankful for about each other? Well, this is a good time to remember those things. How does God want you to respond when your brother or sister is not pleasant?"
"That's right, he wants you to return good for evil. Excellent! Let's pray and maybe I can spend a little bit playing with you two."