It is obvious therefore that this is the conclusion which the mass of mankind draw from a disbelief in immortality. Convince men that this life is all, that death is final extinction, and they will eagerly drain this life of all the pleasure it can yield. We may say that there are some men to whom virtue is the greatest pleasure: we may say that to all the denial of appetite and self-indulgence is a more genuine pleasure than the gratification of it: we may say that virtue is its own reward, and that irrespective of the future it is right to live now spiritually and not sensually, for God and not for self: we may say that the judgments of conscience are pronounced without any regard to future consequences, and that the highest and best life for man is a life in conformity to conscience and in fellowship with God, whether such life is to be long or short, temporal or eternal. And this is true, but how are we to get men to accept it? Teach men to believe in a future life and you strengthen every moral sentiment and every Godward aspiration by revealing the true dignity of human nature. Make men feel that they are immortal beings, that this life, so far from being all, is the mere entrance and first step to existence; make men feel that there is open to them an endless moral progress, and you give them some encouragement to lay the foundations of this progress in a self-denying and virtuous life in this world. Take away this belief, encourage men to think of themselves as worthless little creatures that come into being for a few years and are blotted out again for ever, and you destroy one mainspring of right action in men. It is not that men do noble deeds for the sake of reward: the hope of reward is scarcely a perceptible influence in the best of men, or indeed in any men; but in all men trained as we are, there is an indefinite consciousness that, being immortal creatures, we are made for higher ends than those of this life, and have prospects of enjoyments which should make us independent of the grosser pleasures of the present bodily condition.
Apparently the Corinthians themselves had argued that morality was quite independent of a belief in immortality. For Paul goes on: "Be not deceived:" you cannot, however much you may think so, you _cannot_ hear such theories without having your moral convictions undermined and your tone lowered. This he conveys to them in a common quotation from a heathen poet--"Evil communications corrupt good manners;" that is to say, false opinions have a natural tendency to produce unsatisfactory and immoral conduct. To keep company with those whose conversation is frivolous or cynical, or charged with dangerous or false views of things, has a natural tendency to lead us to a style of conduct we should not otherwise have fallen into. Men do not always recognise this; they need the warning, "Be not deceived." The beginnings of conduct are so hidden from our observation, our lives are formed by influences so imperceptible, what we hear sinks so insidiously into the mind and mingles so insensibly with our motives, that we can never say _what_ we have heard without moral contamination. No doubt it is possible to hold the most erroneous opinions and yet to keep the life pure; but they are strong and guileless spirits who can preserve a high moral tone while they have lost faith in those truths which mainly nourish the moral nature of the mass of men. And many have found to their surprise and grief that opinions which they fancied they might very well hold and yet live a high and holy life, have somehow sapped their moral defences against temptation and paved the way for shameful falls. We cannot always prevent doubts, even about the most fundamental truths, from entering our minds, but we can always refuse to welcome such doubts, or to be proud of them; we can always be resolved to treat sacred things in a reverent and not in a flippant spirit, and we can always aim at least at an honest and eager seeking for the truth.