38 Each individual layman must stand before the world as a witness to the resurrection and life of the Lord Jesus and a symbol of the living God. All the laity as a community and each one according to his ability must nourish the world with spiritual fruits. They must diffuse in the world that spirit which animates the poor, the meek, the peace makers—whom the Lord in the Gospel proclaimed as blessed. In a word, "Christians must be to the world what the soul is to the body."
Source: Lumen Gentium (Vatican.va)