Hope is one of the Theological virtues. This means that a continual looking forward to the eternal world is not (as some modern people think) a form of escapism or wishful thinking, but one of the things a Christian is meant to do. It does not mean that we are to leave the present world as it is. If you read history you will find that the Christians who did most for the present world were just those who thought most of the next.
C. S. LewisShe looked at a silver birch: it would have a soft, showery voice and would look like a slender girl, with hair blown all about her face and fond of dancing. She looked at the oak: he would be a wizened, but hearty, old man with a frizzled beard and warts on his fact and hands, with hair growing out of the warts. She looked at the beech under which she was standing. Ah! --she would be the best of all. She would be a gracious goddess, smooth and stately, the Lady of the Wood.
C. S. Lewis