§1. Members of these institutes express and exercise their own consecration in apostolic activity, and like leaven they strive to imbue all things with the spirit of the gospel for the strengthening and growth of the Body of Christ.
§2. In the world and from the world, lay members participate in the evangelizing function of the Church whether through the witness of a Christian life and of fidelity toward their own consecration, or through the assistance they offer to order temporal things according to God and to inform the world by the power of the gospel. They also cooperate in the service of the ecclesial community according to their own secular way of life.
§3. Through the witness of consecrated life especially in the presbyterium, clerical members help their brothers by a particular apostolic charity, and by their sacred ministry among the people of God they bring about the sanctification of the world.
Source: Code of Canon Law (Vatican.va)