From Pope St. John Paul II’s encyclical Fides et Ratio (1984):
The truth of Christian Revelation, found in Jesus of Nazareth, enables all men and women to embrace the “mystery” of their own life. As absolute truth, it summons human beings to be open to the transcendent, whilst respecting both their autonomy as creatures and their freedom. At this point the relationship between freedom and truth is complete, and we understand the full meaning of the Lord’s words: “You will know the truth, and the truth will make you free” (Jn 8:32).
Christian Revelation is the true lodestar of men and women as they strive to make their way amid the pressures of an immanentist habit of mind and the constrictions of a technocratic logic. It is the ultimate possibility offered by God for the human being to know in all its fullness the seminal plan of love which began with creation. To those wishing to know the truth, if they can look beyond themselves and their own concerns, there is given the possibility of taking full and harmonious possession of their lives, precisely by following the path of truth. Here the words of the Book of Deuteronomy are pertinent: “This commandment which I command you is not too hard for you, neither is it far off. It is not in heaven that you should say, ‘Who will go up for us to heaven, and bring it to us, that we may hear it and do it?’ Neither is it beyond the sea, that you should say, ‘Who will go over the sea for us, and bring it to us, that we may hear and do it?’ But the word is very near you; it is in your mouth and in your heart, that you can do it” (30:11-14). This text finds an echo in the famous dictum of the holy philosopher and theologian Augustine: “Do not wander far and wide but return into yourself. Deep within man there dwells the truth” (Noli foras ire, in te ipsum redi. In interiore homine habitat veritas).21
These considerations prompt a first conclusion: the truth made known to us by Revelation is neither the product nor the consummation of an argument devised by human reason. It appears instead as something gratuitous, which itself stirs thought and seeks acceptance as an expression of love. This revealed truth is set within our history as an anticipation of that ultimate and definitive vision of God which is reserved for those who believe in him and seek him with a sincere heart. The ultimate purpose of personal existence, then, is the theme of philosophy and theology alike. For all their difference of method and content, both disciplines point to that “path of life” (Ps 16:11) which, as faith tells us, leads in the end to the full and lasting joy of the contemplation of the Triune God.
21 De Vera Religione, XXXIX, 72: Corpus Christianorum, Latin series 32, 234.
— Fides et Ratio 15