The central document of the Second Vatican Council, Lumen Gentium was promulgated by Pope Paul VI on November 21, 1964.
This document is "the keystone" of the Council's whole Magisterium. It focuses on the whole Church as a communion of charity. With it, according to John Paul II, the Second Vatican Council wished to shed light on the Church's reality: a wonderful but complex reality consisting of human and divine elements, visible and invisible. To understand the Church, it is necessary to begin with her mystery. The Church is grafted onto Christ and rooted in the life of the Trinity.
The Church described in Lumen Gentium is a Church rich in life; a Church which, far from withdrawing into herself, is opening up with greater energy to the world. Referring to the institutional structure of the Church the document states that all the faithful, who make up the Church, are the People of God. Both clergy and people, as baptized believers, belong to the same community of faith, hope and love, and are fundamentally equal. The People of God as a whole are responsible for the life and growth of the Church. The hierarchy is at the service of the community. The document also addressed the collegial and cooperative relationships of the bishops of the world among themselves and with the pope, and their status together as the supreme authority in the Church.