51 Precisely because it is linked to love (cf. Gal 5:6), the light of faith is concretely placed at the service of justice, law and peace. Faith is born of an encounter with God’s primordial love, wherein the meaning and goodness of our life become evident; our life is illumined to the extent that it enters into the space opened by that love, to the extent that it becomes, in other words, a path and praxis leading to the fullness of love. The light of faith is capable of enhancing the richness of human relations, their ability to endure, to be trustworthy, to enrich our life together. Faith does not draw us away from the world or prove irrelevant to the concrete concerns of the men and women of our time. Without a love which is trustworthy, nothing could truly keep men and women united. Human unity would be conceivable only on the basis of utility, on a calculus of conflicting interests or on fear, but not on the goodness of living together, not on the joy which the mere presence of others can give. Faith makes us appreciate the architecture of human relationships because it grasps their ultimate foundation and definitive destiny in God, in his love, and thus sheds light on the art of building; as such it becomes a service to the common good. Faith is truly a good for everyone; it is a common good. Its light does not simply brighten the interior of the Church, nor does it serve solely to build an eternal city in the hereafter; it helps us build our societies in such a way that they can journey towards a future of hope. The Letter to the Hebrews offers an example in this regard when it names, among the men and women of faith, Samuel and David, whose faith enabled them to "administer justice" ( Heb 11:33). This expression refers to their justice in governance, to that wisdom which brings peace to the people (cf. 1 Sam 12:3-5; 2 Sam 8:15). The hands of faith are raised up to heaven, even as they go about building in charity a city based on relationships in which the love of God is laid as a foundation.
Source: Lumen Fidei (Vatican.va)