The Second Vatican Council didn’t correct a new heresy or define a new doctrine. Nor was it merely the idea of John XXIII. Several cardinals had privately urged Pope John to call a council — including Alfredo Cardinal Ottaviani, who later became the council’s leading conservative, a man whom some reformers loved to criticize.

John XXIII set the goal of Vatican II in his opening remarks: “The greatest concern of the ecumenical council is this: that the sacred deposit of Christian doctrine should be guarded and taught more efficaciously.” To do that he wanted the council not to “reinvent” or “re-imagine” the Church, but to renew the methods, forms, and structures of the Church according to the needs of the modern world, always “recognizing that the substance of the ancient doctrine of the deposit of faith is one thing, and the way it is presented is another.”

In other words, the Church today has exactly the same goal as in 1956: the proclamation of the Lord Jesus Christ for the conversion and salvation of the world, through the truth of the Catholic Faith. The methods and structures may differ, but the mission remains.

The genius of Vatican II was its scope. Over a three-year period, in 16 documents, it examined, purified, renewed, and reaffirmed nearly every aspect of Catholic life. In a very logical way, the council’s four major constitutions give us a catechesis on the whole Christian Faith.

For example, Catholics have always believed that lex orandi, lex credendi — in other words, we worship as we believe, and believe as we worship. So in 1963, the council issued the Constitution on the Sacred Liturgy as its very first document, because our worship at the Eucharistic meal and sacrifice of the Mass is the cornerstone of our belief and of everything else that makes us distinctively Catholic.

In 1964, the council defined who and what the community of Faith is in Lumen Gentium, the Dogmatic Constitution on the Church. Christ founded the Church before anyone wrote the first word of the first Gospel. The Church came first. The Holy Spirit inspired the Evangelists to write down God’s Word fully and truthfully, but it was the community of believers that reflected on it, organized it, and interpreted it. The Church precedes the Bible, not the other way around.

In the last weeks of Vatican II, the council issued the Dogmatic Constitution on Divine Revelation and the Pastoral Constitution on the Church in the Modern World. The council’s work was then complete.

Too many times over the past four decades, people have claimed to be the Church or to speak as the voice of the faithful and then acted or taught in ways that seemed to oppose what the Church actually believes.

When people say, “We are the Church,” of course that’s true. We’re all the Church, because the Church is the community of the faithful. But a “community of the faithful” implies that there’s someone and something we have the duty to be faithful to. We don’t invent the Catholic Faith, nor do we own it. We receive it; we live it in community; we witness it to others; and we pass it on fully — if we’re good stewards — to our children. That’s what life in the Church means. And that’s why it’s worth reflecting on the content of Lumen Gentium, the Dogmatic Constitution on the Church.

Blessed John XXIII often described the Catholic Church as the “mother and teacher of all nations.” In opening the Second Vatican Council, he said that “the Church, surrounded by divine light, spreads her rays over the entire earth.” That’s what the Latin words Lumen Gentium mean: “light to the nations.” That’s what God created us to be. That’s the reality of the Church we all belong to — not some religious corporation or the Elks Club at prayer; but the glory of Jesus Christ alive and risen, and God’s light to the world.

Not all of Lumen Gentium is easy reading, but it’s worth the effort, because this document does a wonderful job of teaching us who and what the Catholic Church is. The Dogmatic Constitution presents the Church in a range of beautiful images from Scripture and Catholic tradition. Each of the images is important and true, but none can stand alone outside the context of the others.

The Church is a sheepfold of safety, with Jesus as the only gate. It is also God’s flock, and also His tillage — the land He cultivates to bring new life to the world. The Church is God’s building, with Jesus as the foundation and each of us its living stones. The Church is the spotless spouse of Christ and the family of God. It is an exile and pilgrim in the world. The Church is also a sacrament — a sign and instrument of communion with God and unity among men and women.

Above all, the Church is the mystical Body of Christ and the new Israel; the new, messianic People of God with Jesus as our head. It is the new royal priesthood, with all Christians living in fundamental equality through baptism, but like a family, having a diversity of duties and organized in a hierarchy of roles.

Religious and consecrated persons bear witness to the Beatitudes by living poverty, chastity, and obedience in a radical way. Laypeople, because they live in the daily secular world, have the missionary task of humanizing society and converting it to Jesus Christ. And the ordained have the vocation of service to the Church; feeding the faithful through the Eucharist and other sacraments; and teaching, sanctifying, encouraging, and governing for the sake of God’s people. But all members of the Church have exactly the same call to holiness according to the circumstances of their lives.

Lumen Gentium reminds us that no one is saved except through Jesus Christ, and that the Catholic Church is the true Church of Christ, necessary for salvation. As a result, no one can be saved “who, knowing that the Catholic Church was founded as necessary by God through Christ, would refuse either to enter it, or to remain in it.”

But God is also a merciful Father; He seeks the salvation of all men and women. Therefore, Lumen Gentium also teaches that those “who, through no fault of their own, do not know the Gospel of Christ or His Church, but who nevertheless seek God with a sincere heart, and moved by grace, try in their actions to do His will as they know it through the dictates of their conscience — those too may achieve eternal salvation.”

But perhaps the most moving quality of Lumen Gentium is the way it begins and ends with a person. It begins with the person of Jesus Christ as the savior of humanity and the meaning of history. And it ends with the person of Mary, His mother and our mother, and an icon of what we can all be — and what the Church will be — in her perfection. When we claim that “we are the Church,” Mary’s humility, obedience, fidelity, and love are what we should mean.

Last October marked the 43rd  anniversary of one of the final documents of the council, Christus Dominus (Christ the Lord), or the Decree on the Pastoral Office of Bishops in the Church. The first line of the conciliar text reads, “Christ the Lord, the Son of the Living God, came to redeem His people from their sins, that all mankind might be sanctified.” It reminds bishops that our first duty is to proclaim the Lordship of Jesus Christ — to give up our own lives and live as Jesus Christ for the service of the persons in our care.

Vatican II described the vocation of bishops as a call to serve rather than a call to power. When a bishop struggles to put on Jesus Christ over his own sins and weaknesses, he begins to understand why the council talks about the pastoral office of bishops in the Church, and not outside or above it. Bishops have the same need for redemption as the people to whom we belong. The only difference is that God will hold bishops even more accountable because of the leadership to which He ordained us, and because of the graces of the office we receive.

Christus Dominus is a curious mix of housekeeping and theology. Much of the document deals with very practical matters — redrawing diocesan boundaries, how long pastors should serve in parishes, when to ask for an auxiliary bishop, and the role of the diocesan staff. But all of the practical issues in Christus Dominus rest on the document’s spiritual foundation, which comes from Lumen Gentium and the ancient traditions of the Church.

The early Church Father St. Ignatius of Antioch, no stranger to Church controversy, reminded and cautioned Christians that “those [who] belong to God and to Jesus Christ — they are with the bishop.”

Every bishop is a successor to the apostles and a pastor of souls. He has the duty to safeguard the liturgical life of the local Church. He must proclaim the gospel and teach the true Catholic faith in his diocese. Every bishop should give an example of personal sanctity in charity, humility, and simplicity of life. He should help the poor and suffering. He has the obligation to sanctify, encourage, correct, and govern the local people of God. And above all, every bishop needs to do these things with fatherly love and fraternal charity, because the Church is a family — a family of faith — not a political party or an impersonal institution.

This is why bishops are always so reluctant to excommunicate anybody, even a grave public criminal or a Catholic public official who directly opposes Church teaching on a serious matter. A good father will do almost anything, and bear almost any insult or burden, to keep his daughter or son in the family.

And he owes that same fidelity to his priests. Vatican II commands bishops to support their priests, and to treat them as sons and brothers. In Catholic teaching, a priest shares intimately in the mission of his bishop through the Sacrament of Orders. A priest is never simply an “employee” of the Church, and the bishop is forbidden to treat him that way.