This is a portion of an article I found online written by Dr. Martin Lloyd-Jones. If you would like to read the entire article you can find it here.
The glory of the gospel is that when the Church is absolutely different from the world, she invariably attracts it. It is then that the world is made to listen to her message, though it may hate it at first. That is how revival comes. That must also be true of us as individuals. It should not be our ambition to be as much like everybody else as we can, though we happen to be Christian, but rather to be as different from everybody who is not a Christian as we can possibly be. Our ambition should be to be like Christ, the more like Him the better, and the more like Him we become, the more we shall be unlike everybody who is not a Christian.
Let me show you this in detail. The Christian and the non-Christian are absolutely different in what they admire. The Christian admires the man who is ‘poor in spirit’, while the Greek philosophers despised such a man, and all who follow Greek philosophy, whether intellectually or practically, still do exactly the same thing. What the world says about the true Christian is that he is a weakling, an apology for a man, or that he isn’t manly. Those are its expressions. The world believes in self-confidence, self-expression and the mastery of life; the Christian believes in being ‘poor in spirit’. Take the newspapers and see the kind of person the world admires. You will never find anything that is further removed from the Beatitudes than that which appeals to the natural man and the man of the world. What calls forth his admiration is the very antithesis of what you find here. The natural man likes an element of boastfulness, but that is the very thing that is condemned in the Beatitudes.
Then, obviously, they must be different in what they seek. ‘Blessed are they which do hunger and thirst.’ After what? Wealth, money, status, position, publicity? Not at all. ‘Righteousness.’ And righteousness is being right with God. Take any man who does not claim to be a Christian and who is not interested in Christianity. Find out what he is seeking and what he really wants, and you will see it is always different from this.
Then, of course, they are absolutely different in what they do. That follows of necessity. If they admire and seek different things, they very clearly do different things. The result is that the life which is lived by the Christian must be an essentially different life from that of the man who is not a Christian. The non-Christian is absolutely consistent. He says he lives for this world. ‘This’, he says, ‘is the only world, and I am going to get all I can out of it.’ Now the Christian starts by saying he is not living for this world; he regards this world as but the way of entry into something vast and eternal and glorious. His whole outlook and ambition is different. He feels, therefore, that he must be living in a different way. As the man of the world is consistent, so the Christian also ought to be consistent. If he is, he will be very different from the other man; he cannot help it. Peter puts it perfectly in the second chapter of his first Epistle when he says that if we truly believe that we are a people who have been called ‘out of darkness into his marvelous light’, we must believe that this has happened to us in order that we might show forth His praises. Then he goes on to say: ‘I beseech you as strangers and pilgrims (those of you who are in this world), abstain from fleshly lusts, which war against the soul; having your conversation honest among the Gentiles: that, whereas they speak against you as evildoers, they may by your good works, which they shall behold, glorify God in the day of visitation’ (I Pet. ii. 11,12). That is nothing but an appeal to their sense of logic.