The second document of Vatican II is Lumen Gentium, which is about the church. This is a longer document than Dei Verbum, so I might need to discuss it in three parts, not two.
The first section of the document is on the mystery of the church. It describes the role of the church, throughout all of salvation history. It then goes into detail about various metaphors which are used to describe the church, such as "the house of God", "our mother", "the bride of Christ", and "the vineyard of the Lord". The most important title for the church, which is not a metaphor, is "the Mystic Body of Christ". All the members are the church are united to Christ, through the sacraments, which not only symbolize our oneness with Christ, but also bring it about. "All the members ought to be molded in the likeness of Him, until Christ be
formed in them."
One major problem that occurs is that people will try to separate the church from the church. I've seen this happen in various ways. For example, I've heard people say things like "the Spanish community here is a completely different church", "what they do in Rome doesn't affect us here in America" and "things were different in the 1950's". The truth is, you can't split up the church by language, location, or time, simply because the church transcends all these things. The one church of Christ has existed, unchanged, in all languages, places and times.
The document makes a particular point to not separate the human and divine elements of the church. This is a mistake that has been present since the very beginning; in our times, the tendency is to replace divine elements with unsuitable human elements. Jesus Christ was both fully god and fully human; the church he founded, likewise, is partially human and partially divine. Trying to separate the two is as foolish as trying to separate the church in Heaven from the church on Earth.
The second part of the document is on the people of God. The people of God are one, reborn in the new covenant established by Christ's blood, which made them "a chosen race...a holy nation, God's own people". They are "a lasting and sure seed of unity, hope and salvation for the whole human race". Through baptism, a person becomes one of God's people, and he or she is transformed in a priest and prophet.
A person who is baptised is made into a priest, in that he or she is consecrated as holy to God, and he or she can now offer spiritual sacrifices to God and proclaim the power of Christ. Of course, the priesthood confirmed during baptism is essentially different from the ordained priesthood (in the same way a dog is essentially different from a cat), but the two are related, because they are both a participation in the priesthood of Christ.
The document goes on to describe the sacraments, which nourish, unite and perfect the people of God. The people of God actively participate in the sacraments, instead of passively receiving them. The Eucharistic sacrifice is of particular note, because it is "the source and summit of the whole Christian life".
A person who is baptised is made into a prophet, in that he or she becomes a living witness to God, "especially by means of a life of faith and charity". As prophets, they are led by the Holy Spirit, who gives them supernatural discernment of matters of faith and morals. "The people of God adheres unwaveringly to the faith given once and for all to the saints, penetrates it more deeply with right thinking, and applies it more fully in its life."
"All men are called to belong to the new people of God"; they are all called to be members of the universal Catholic Church. The document first turns its attention on the Catholic faithful, who know that the Church is necessary for salvation, as Christ has affirmed the necessity of faith and baptism in explicit terms. Attention then turns to Christians, who are united in Christ through baptism, but not fully united in that they do not profess the faith in its entirety or maintain communion with the Pope; the Catholic Church constantly prays, hopes and works, so that these people who broke off from the church may return.
Attention is finally given to non-Christians. God wills that all people be saved, and so he is not far distant from them; he makes his will known to them through the dictates of the conscience. Sadly, many people have deformed their consciences; "they have become vain in their reasonings and have exchanged the truth of God for a
lie, serving the creature rather than the Creator." And so, as far as non-Christians are concerned, we must remember the command to preach the Gospel to every creature, to carry the Gospel to the ends of the Earth. "The Church both prays and labors in order that the entire world may become the
People of God".