Catechism of the Catholic Church

928 "A secular institute is an institute of consecrated life in which the Christian faithful living in the world strive for the perfection of charity and work for the sanctification of the world especially from within." ⁴⁷²

929 By a "life perfectly and entirely consecrated to [such] sanctification," the members of these institutes share in the Church's task of evangelization, "in the world and from within the world," where their presence acts as "leaven in the world." ⁴⁷³ "Their witness of a Christian life" aims "to order temporal things according to God and inform the world with the power of the gospel." They commit themselves to the evangelical counsels by sacred bonds and observe among themselves the communion and fellowship appropriate to their "particular secular way of life." ⁴⁷⁴