26 This being the case, can Christian faith provide a service to the common good with regard to the right way of understanding truth? To answer this question, we need to reflect on the kind of knowledge involved in faith. Here a saying of Saint Paul can help us: "One believes with the heart" ( Rom 10:10). In the Bible, the heart is the core of the human person, where all his or her different dimensions intersect: body and spirit, interiority and openness to the world and to others, intellect, will and affectivity. If the heart is capable of holding all these dimensions together, it is because it is where we become open to truth and love, where we let them touch us and deeply transform us. Faith transforms the whole person precisely to the extent that he or she becomes open to love. Through this blending of faith and love we come to see the kind of knowledge which faith entails, its power to convince and its ability to illumine our steps. Faith knows because it is tied to love, because love itself brings enlightenment. Faith’s understanding is born when we receive the immense love of God which transforms us inwardly and enables us to see reality with new eyes.
Source: Lumen Fidei (Vatican.va)