In general, is an assent of the mind to the truth of some proposition on the word of another, God or man. It differs from assent in matters of science in that the latter is based on evidence of fact, whereas the former is based solely on the word of another. Divine faith is therefore the holding of some truth as absolutely certain because God, Who can neither deceive nor be deceived, has spoken it. It is not merely a feeling or a suspicion or an opinion, but a firm, unshakeable adherence of the mind to a truth revealed by God. The motive of Divine faith, or the reason why we believe, is God's authority, His unfailing knowledge and truthfulness. We believe the truths of faith not because our minds understand them, can see them, but because the Infinitely Wise and Truthful God has revealed them.
This motive of faith must not be confused with motives of credibility. These latter are the signs, and among them the surest are miracles and prophecies, by which we can conclude with full certitude that God has revealed and that therefore there is a strict obligation to accept the truths He has made known. It is these motives of credibility which precede the act of faith and which make it essentially reasonable to assent to the truths of faith, for once it is certain that God has spoken, it is unreasonable to withhold assent to His truths. All that God has revealed and nothing else is the object of Divine faith, for it is that and that alone which can be accepted on the word of God. Though a man may be able by his own resources to learn the main truths revealed by God, the normal and usual way is through the Church which has been commissioned by Christ to teach in His name and with His authority. Divine faith is a supernatural act and therefore requires the grace of God. This grace is given to all adults who do not place any obstacle in its way. Without faith no man can be saved. For infants the virtue of faith received at the time of Baptism suffices, but for adults an act of supernatural faith that God exists and rewards the good and punishes the evil is necessary for salvation.
New Catholic Dictionary
