The first part of Gaudium et Spes, entitled “The Church and Man's Vocation,” discusses four main themes in four chapters: the dignity of human beings, the community of mankind, human activity, and the Church's role in the modern world.
Here are some of the topics and ideas you'll find in Part I, Chapter IV, of Gaudium et Spes.
Chapter IV – Role of the Church in the Modern World
Mutual Relationship of Church and World
* The Church is present on earth in history and is made up of human beings who form a visible society and the family of God.
* At the same time, the Church is a “spiritual community” with a “saving and eschatological purpose” that will be fulfilled only in the “next life.”
* The Church journeys with humanity, serves as the “soul of human society,” and casts the light of God upon the whole world. The Church provides deeper meaning to all human life as she promotes human dignity and communicates the divine life.
What the Church Offers to Individuals
* The Church opens up the mystery of God to humanity and offers meaning and truth.
* Human beings are always searching for the answers to their deepest questions. The Church provides answers, for she proclaims the redeeming work of Christ and the fulfillment of humanity in Christ.
* The Church defends human dignity and freedom; announces the Gospel of salvation; promotes service and love; and proclaims human rights.
What the Church Offers to Society
* Through the Church, human beings, with the grace of God, work toward unity, peace, love, service, and a lived faith.
* The Church has a universal mission to draw all people together into one family, united by the divine law and the love of God.
* “Whatever truth, goodness, and justice is to be found in past or present human institutions is held in high esteem” by the Church, which encourages these qualities and the common good of all people.
What the Church Offers to Human Activity through Its Members
* Christians, as citizens of both heaven and earth, must “perform their duties faithfully in the spirit of the Gospel.” Their Christian faith ought to permeate their entire lives and all their activities.
* The laity, especially, are called to “animate the world” with the spirit of Christ and to be witnesses in all circumstances. They must “become truly proficient” in their particular spheres; properly inform their consciences; abide by the divine law in all their affairs; take responsibility for spreading the Gospel; allow themselves to be guided by the Church; and to let the “light of the Gospel” shine through them.
* The Church is “an inexhaustible font” of the resources the world needs to reach its fulfillment as the family of God. She is both the “faithful spouse of the Lord” and the “sign of salvation in the world,” but she is also always in need of purification and renewal in Christ.
What the Church Receives from the Modern World
* The Church has always “profited from the history and development of mankind.” She uses the “concepts and language” of different cultures to express and explain the Gospel.
* Guided by the Holy Spirit, the Church listens carefully to the voices of each era and interprets them according to Divine Revelation “in order that the revealed truth may be more deeply penetrated, better understood, and more suitably presented.”
* Cultural and technological advancements contribute to the Church in as much as they are used “according to the plan of God.”
Christ: Alpha and Omega
* The Church has one single purpose: “that the kingdom of God may come and the salvation of the human race may be accomplished." She is the “universal sacrament of salvation” that manifests and actualizes “the mystery of God's love” for humanity.
* Jesus is the center and goal of all human history and civilization. He is the “joy of all hearts” and “the fulfillment of all aspirations.” All people, all things, all history, and the whole world are called to unity in Him.
The full text of Gaudium et Spes is available online at the Vatican website.