Here is one attempt to do so.
If we consider the development of human beings, we find that a person needs to grow into a sense of one's own meaning and purpose. Every person coming to maturity needs to have a stable sense of her own identity, which is something deeper than a mere "role" or "occupation," for we are more than what we do. We have dignity which allows us to accept ourselves as fundamentally valuable, even as we view ourselves as having strengths and weaknesses.
If we consider the development of human communities, we find a similar need to reflect on the community's identity. Vatican II was, in fact, the first systematic reflection on the mystery of the church's very identity.
We are all familiar with "mission statements" which propose to describe the meaning of a community or corporation in terms of its activity. Jesus himself gave his followers a "mission" to engage in the activity of announcing the Good News of his victory over sin and death.
We cannot go on mission, however, if we do not know who we are. The Council gave the church an opportunity to reflect deeply on the identity of God's people so that we can integrate a sense of who we are with what we do.
The Dogmatic Constitution on the Church (Lumen Gentium or Light of the World), one of the 16 documents of Vatican II, guides our reflection on the identity of the church and its members. The starting point is the baptism which every Christian undergoes.
Baptism is the sacramental means by which people become incorporated into the mystery of the death and resurrection of Jesus, true God and true man. Each new Christian shares in the astonishing thing which Jesus did when he laid down his life. In going under the water of baptism, each of us participates in the death of Jesus. Emerging from the water, we share in the resurrection. Eternal life begins with baptism.
Every one of us, through baptism, is called to holiness, which is not some unreal and unearthly existence but rather a real confrontation of life as we meet it. Within the universal call to holiness, each individual will live a unique life.
It is necessary that we, the members of the Body of Christ, consider what we have in common. Our baptism makes us sharers in salvation. We tread in territory opened for us by the crucified and risen Jesus. Together we are amazed at being participants in the merciful work by which we are set free to live out a call to love.
The Second Vatican Council gave all of us an opportunity to embrace our identity as healed, saved, and lifted up by the gift of Jesus Christ. We know that the world and all its people have need of this gift. Vatican II remains an occasion for reflection on the dignity of human beings, and the lavish love of God toward us.