From henceforth, brethren, whatever things be sooth, whatever things chaste, whatever things just, whatever things holy, whatever things able to be loved, whatever things of good fame, if any virtue, if any praising of discipline, think ye (on) these things,
Does Paul mean that we should fake it? – that we should just act positive no matter how we think or feel. No, I don’t think so. I believe he’s saying that we ought to be so enamoured with the Word of God that it transforms our thinking – our very pattern of thought so that our actions mirror our thoughts. And our thoughts ought to mirror God’s thoughts.
Not sure what God is thinking? Read His Word. Then you’ll know.