Christianity asserts that every individual human being is going to live for ever, and this must be either true or false. Now there are a good many things which would not be worth bothering about if I were going to live only seventy years, but which I had better bother about very seriously if I am going to live forever. Perhaps my bad temper or my jealousy are gradually getting worse–so gradually that the increase in seventy years will not be very noticeable. But it might be absolute hell in a million years: in fact, if Christianity is true, Hell is the precisely correct technical term for what it would be. And immortality makes this other difference, which, by the by, has a connection with the difference between totalitarianism and democracy. If individuals live only seventy years, then a state, or a nation, or a civilisation, which may last for a thousand years, is more important than an individual. But if Christianity is true, then the individual is not only more important but incomparably more important, for he is everlasting and the life of a state or a civilisation, compared with his, is only a moment.
from: C. S. Lewis Mere Christianity: A Revised and Amplified Edition, with a New Introduction, of the Three Books, Broadcast Talks, Christian Behaviour, and Beyond Personality. San Francisco: HarperSanFrancisco, 2001, 74-75.