As Christians, when we are born again into a new life, we are called to act differently than before we accepted Christ as our Savior. Paul describes how we should behave and believe pretty well in Colossians 3:12-17.
The sentence "And be thankful." seems almost like an afterthought, but it is much more powerful than that. Consider what you would be like if the only thing you changed was being grateful for everything. Your attitude and outlook would change. And with those changes, you couldn't help but become more Christ-like. Try it today. Try being thankful for everything and everyone you encounter today and see if that affects your actions and attitude as well. Then, let me know how your experiment went. I'd love to hear all about it!
Let the peace of Christ rule in your hearts, since as members of one body you were called to peace. And be thankful. Colossians 3:15