34 Throughout the course of the centuries, men have labored to better the circumstances of their lives through a monumental amount of individual and collective effort. To believers, this point is settled: considered in itself, this human activity accords with God's will. For man, created to God's image, received a mandate to subject to himself the earth and all it contains, and to govern the world with justice and holiness; a mandate to relate himself and the totality of things to Him Who was to be acknowledged as the Lord and Creator of all. Thus, by the subjection of all things to man, the name of God would be wonderful in all the earth. This mandate concerns the whole of everyday activity as well. For while providing the substance of life for themselves and their families, men and women are performing their activities in a way which appropriately benefits society. They can justly consider that by their labor they are unfolding the Creator's work, consulting the advantages of their brother men, and are contributing by their personal industry to the realization in history of the divine plan. Thus, far from thinking that works produced by man's own talent and energy are in opposition to God's power, and that the rational creature exists as a kind of rival to the Creator, Christians are convinced that the triumphs of the human race are a sign of God's grace and the flowering of His own mysterious design. For the greater man's power becomes, the farther his individual and community responsibility extends. Hence it is clear that men are not deterred by the Christian message from building up the world, or impelled to neglect the welfare of their fellows, but that they are rather more stringently bound to do these very things.
Source: Gaudium et Spes (Vatican.va)