16 No one, however, must entertain the notion that private individuals are prevented from taking some active part in this duty of teaching, especially those on whom God has bestowed gifts of mind with the strong wish of rendering themselves useful. These, so often as circumstances demand, may take upon themselves, not, indeed, the office of the pastor, but the task of communicating to others what they have themselves received, becoming, as it were, living echoes of their masters in the faith. Such co-operation on the part of the laity has seemed to the Fathers of the Vatican Council so opportune and fruitful of good that they thought well to invite it. "All faithful Christians, but those chiefly who are in a prominent position, or engaged in teaching, we entreat, by the compassion of Jesus Christ, and enjoin by the authority of the same God and Saviour, that they bring aid to ward off and eliminate these errors from holy Church, and contribute their zealous help in spreading abroad the light of undefiled faith."(16) Let each one, therefore, bear in mind that he both can and should, so far as may be, preach the Catholic faith by the authority of his example, and by open and constant profession of the obligations it imposes. In respect, consequently, to the duties that bind us to God and the Church, it should be borne earnestly in mind that in propagating Christian truth and warding off errors the zeal of the laity should, as far as possible, be brought actively into play.
Source: Sapientiae Christianae (Vatican.va)