CATECHISM OF THE CATHOLIC CHURCH
SECOND EDITION

Paragraphs 157–161

157 Faith is certain. It is more certain than all human knowledge because it is founded on the very word of God who cannot lie. To be sure, revealed truths can seem obscure to human reason and experience, but "the certainty that the divine light gives is greater than that which the light of natural reason gives." "Ten thousand difficulties do not make one doubt."
158 "Faith seeks understanding": it is intrinsic to faith that a believer desires to know better the One in whom he has put his faith, and to understand better what He has revealed; a more penetrating knowledge will in turn call forth a greater faith, increasingly set afire by love. The grace of faith opens "the eyes of your hearts" to a lively understanding of the contents of Revelation: that is, of the totality of God's plan and the mysteries of faith, of their connection with each other and with Christ, the center of the revealed mystery. "The same Holy Spirit constantly perfects faith by his gifts, so that Revelation may be more and more profoundly understood." In the words of St. Augustine, "I believe, in order to understand; and I understand, the better to believe."
159 Faith and science: "Though faith is above reason, there can never be any real discrepancy between faith and reason. Since the same God who reveals mysteries and infuses faith has bestowed the light of reason on the human mind, God cannot deny himself, nor can truth ever contradict truth." "Consequently, methodical research in all branches of knowledge, provided it is carried out in a truly scientific manner and does not override moral laws, can never conflict with the faith, because the things of the world and the things of faith derive from the same God. The humble and persevering investigator of the secrets of nature is being led, as it were, by the hand of God in spite of himself, for it is God, the conserver of all things, who made them what they are."
160 To be human, "man's response to God by faith must be free, and... therefore nobody is to be forced to embrace the faith against his will. The act of faith is of its very nature a free act." "God calls men to serve him in spirit and in truth. Consequently they are bound to him in conscience, but not coerced. . . This fact received its fullest manifestation in Christ Jesus." Indeed, Christ invited people to faith and conversion, but never coerced them. "For he bore witness to the truth but refused to use force to impose it on those who spoke against it. His kingdom... grows by the love with which Christ, lifted up on the cross, draws men to himself."
161 Believing in Jesus Christ and in the One who sent him for our salvation is necessary for obtaining that salvation. "Since "without faith it is impossible to please [God]" and to attain to the fellowship of his sons, therefore without faith no one has ever attained justification, nor will anyone obtain eternal life 'But he who endures to the end.'"