The truth is that the imbalances under which the modern world labors are linked with that more basic imbalance which is rooted in the heart of man. For in man himself many elements wrestle with one another. Thus, on the one hand, as a creature he experiences his limitations in a multitude of ways; on the other he feels himself to be boundless in his desires and summoned to a higher life. Pulled by manifold attractions he is constantly forced to choose among them and renounce some. Indeed, as a weak and sinful being, he often does what he would not, and fails to do what he would.(Cf. Rom. 7:14 ff.) Hence he suffers from internal divisions, and from these flow so many and such great discords in society. No doubt many whose lives are infected with a practical materialism are blinded against any sharp insight into this kind of dramatic situation; or else, weighed down by unhappiness they are prevented from giving the matter any thought. Thinking they have found serenity in an interpretation of reality everywhere proposed these days, many look forward to a genuine and total emancipation of humanity wrought solely by human effort; they are convinced that the future rule of man over the earth will satisfy every desire of his heart. Nor are there lacking men who despair of any meaning to life and praise the boldness of those who think that human existence is devoid of any inherent significance and strive to confer a total meaning on it by their own ingenuity alone.
Nevertheless, in the face of the modern development of the world, the number constantly swells of the people who raise the most basic questions or recognize them with a new sharpness:
What is man?
What is this sense of sorrow, of evil, of death, which continues to exist despite so much progress?
What purpose have these victories purchased at so high a cost?
What can man offer to society, what can he expect from it?
What follows this earthly life?
The Church firmly believes that Christ, who died and was raised up for all,(Cf, 2 Cor. 5:15) can through His Spirit offer man the light and the strength to measure up to his supreme destiny. Nor has any other name under the heaven been given to man by which it is fitting for him to be saved.(Cf. Acts 4:12) She likewise holds that in her most benign Lord and Master can be found the key, the focal point and the goal of man, as well as of all human history. The Church also maintains that beneath all changes there are many realities which do not change and which have their ultimate foundation in Christ, Who is the same yesterday and today, yes and forever.(Cf. Heb. 13:8) Hence under the light of Christ, the image of the unseen God, the firstborn of every creature,(Cf. Col. 1:15) the council wishes to speak to all men in order to shed light on the mystery of man and to cooperate in finding the solution to the outstanding problems of our time.
Gaudium et Spes, 10