This passage is about the use of the mind, the control of the bodily parts and passions, and the use of the mouth and the words that are spoken. He is concerned about sanctification, progress in holiness.
So, since we are risen with Christ and we have received so much from him, we have got to live, setting our minds and our hopes upon the work of Christ and what he does. Our interests are there. We are like foreign ambassadors, as it were; we have a nation and a government somewhere else. We are here appointed in this country, what for? Well, to carry out the interests of our government. Seek the things which are heavenly – in other words, seek the winning of souls, that is one of the purposes of Christ. Seek holiness, that of course is the great purpose of Christ in bringing home a ransomed people for all eternity. Seek the interests of Christ and his government, his purposes in the world, that is the essential meaning. How should I live today? With an eye on eternity. There I shall be holy, that will be the place of perfection and glory and holiness and praise and worship – I should be preparing for that. Seek the things which relate to heaven and the eternal rule of Christ.
I can remember when I was a young Christian being in a gathering in a church where this was the text. But the preacher gave himself a hard time with it. He seemed to think that what we must seek is a kind of heavenly sensation, heavenly experience. After all, if I were in heaven, if I were above, what would I enjoy, what would I have there? So, to him, the text seems to say, can you not cultivate the taste to enjoy those things even now. But that is not what the apostle here means at all.