PREAMBLES OF FAITH (prawambula fidei). — This expression designates the truths that must and can be known by reason before, through infused faith and actual Grace, the faithful adhere to revealed truths «propter auctoritatem Dei revelantis», that is, on the authority of God who has revealed them.
These preambles of faith are the existence of God and the signs of the divine origin of Revelation. The existence of God, author of nature, can be readily known, even if in a confused manner, from consideration of the nature of created things, their order, etc., which postulate the existence of a creator and supreme ordainer (Wis. 13:2–5). Thus the First Vatican Council defined (Denz-U, 1785): «that God, the beginning and end of all things, can be known with certainty by the natural light of human reason through created things». The Oath against Modernism adds (ibid., 2145): «The existence of God can be rationally demonstrated on the basis of the effects of which God is the cause».
The motives of credibility must also be numbered among the preambles of faith, that is, the signs of the divine origin of the Revelation contained in the Old and New Testaments and in the living Tradition of the Church. These are miracles (especially those of Christ, above all his Resurrection), fulfilled prophecies, the exceptional holiness of Jesus, the sublimity of his doctrine, and the wondrous life of the one, holy, catholic, and apostolic Church, which for twenty centuries has resisted so many causes of division and ruin (Denz-U, 1790, 1794, 1799, 1812, 1813, 2145; V. CREDIBILITÀ RAZIONALE DELLA FEDE CATTOLICA; MIRACOLO; RIVELAZIONE).