Every Catholic has a duty to spread the salvific truths of the Catholic Faith, for without the Church, no one can be saved. It is an act of love to proclaim the truth to lost souls, for their eternal salvation. We cannot share what we do not know, therefore, we have an obligation to learn and study the Faith so that we can defend it, even to our dying breath as the martyrs did. The Baltimore Catechism states that we are in this world to know, love and serve God. To know God, we have to know the truths of the Religion he established. To serve God, we have to put those truths into practice. Our light must shine before men so that they can see our good deeds, our love for our Faith and glorify God themselves by becoming children of God and His Church.
“Tell your faithful children of the laity that when, united with their pastors and their bishops, they participate in the works of the apostolate, both individual and social, the end purpose of which is to make Jesus Christ better known and better loved, then they are more than ever ‘a chosen generation, a kingly priesthood, a holy nation, a purchased people,’ of whom St. Peter spoke in such laudatory terms. (I Peter ii, 9) Then, too, they are more than ever united with Us and with Christ, and become great factors in bringing about world peace because they work for the restoration and spread of the Kingdom of Christ.” ~Pope Pius XI, “Ubi Arcano Dei Consilio”, 1922
“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 [First] 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 Savior, 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.’ 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.” ~Pope Leo XIII, “Sapientiae Christianae”, 1890
~Damsel of the Faith