This document was composed by the Dominican friars who have been imprisoned in Sao Paolo since 1969. It is the outcome of their joint reflections and those of other Christian prisoners with them. It falls into three parts: a meditation on the role of the Church in the world (extensively summarized here), an account of conditions in Brazil, and a consequent justification of the revolutionary position they have adopted.

The Church is the universal sacrament of salvation, continuing in time the presence, mission and work of Christ in the world. Jesus Christ came to make salvation a reality, and his whole life, including his death and resurrection, was a witness of love. The mission of the Church is to continue this living witness of love, and the Church is essentially missionary, sent to the world to witness to Jesus Christ among men.

The Church cannot exist on the fringe of the world; it is in the world and has to be constantly present to the world, since it is there that its mission lies, as light to the world, salt of the earth, the leaven in the dough. This is why the Council produced a Constitution on the Church in the World of Today.