The harmony of faith and reason in the Catholic Church is an old institution. The knowledge that reason can
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 (Catholic Church 159)." “The miracles of Christ and the saints, prophecies, the Church's growth and holiness, and her fruitfulness and stability "are the most certain signs of divine Revelation, adapted to the intelligence of all"; they are "motives of credibility" (motiva credibilitatis), which show that the assent of faith is "by no means a blind impulse of the mind (Catholic Church 156).
Man's God given ability to reason is ultimately a search for the truth. This truth can only be found in God. He is the supreme Truth. This search for the truth, however, is not something that can be forced upon somebody. To do so would be an imposition on free will; a gift which God has given us. That being said religious freedom must be allowed. The knowledge of God's Truth through faith and reasoning can be the guide an individual of another faith needs to be led to the Church. The CCC has this to say on the matter:
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. . . 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 (Catholic Church 160).