“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 . . . all left their mark on Earth, precisely because their minds were occupied with Heaven. It is since Christians have largely ceased to think of the other world that they have become ineffective in this. Aim at Heaven and you will get earth ‘thrown in’: aim at earth and you will get neither. It seems a strange rule, but something like it can be seen in other matters. Health is a great blessing, but the moment you make health one of your main, direct objects, you start becoming a crank and imagining there is something wrong with you. You are only likely to get health provided you want other things more–food, games, work, fun, open air. In the same way, we shall never save civilization as long as civilization is our main object. We must learn to want something else even more.
“Creatures are not born with desires unless satisfaction for those desires exist. A baby feels hunger: well, there is such a thing as food. A duckling wants to swim: well, there is such a thing as water. Men feel sexual desire; well, there is such a thing as sex. If I find in myself a desire which no experience in this life can satisfy, the most probable explanation is that I was made for another world. If none of my earthly pleasures satisfy it, that does not prove that the universe is a fraud. Probably earthly pleasures were never meant to satisfy it, but only to arouse it, to suggest the real thing. If that is so, I must take care, on the one hand, never to despise, or be unthankful for, these earthly blessings; and on the other, never to mistake them for the something else of which they are only a kind of copy, or echo, or mirage. I must keep alive in myself the desire for MY TRUE COUNTRY which I shall not find till after death; I must never let it get snowed under or turned aside; I must make it the main object of life to press on to that other country and help others do the same.
“There is no need to be worried by facetious people who try to make the Christian hope of ‘Heaven’ ridiculous by saying they do not want to ‘spend eternity playing harps’. The answer to such people is that if they cannot understand books written for grown-ups, they should not talk about them.”
C.S. Lewis “Mere Christianity“