For truth-seekers, "this discovery of love as a source of knowledge... finds authoritative expression in the biblical understanding of faith." (LF, 28) Faith allows us to the see the reality that a faithful God enters human history, forms covenantal relationships with human persons, and thus enables them to know the truth about themselves and the world.

Faith-knowledge sheds light not only on the destiny of one particular people, but the entire history of the created world, from its origins to its consummation. (LF, 28)

This is a profound view of truth and how we gain knowledge of it. It links the discovery of truth to a faith founded on a relationship with God. It sees all things through a relational lens: God can be known by us, and God leads us into all knowing. Therefore, approaches to truth that are less than faith-knowledge in God are limited and incomplete.

God is knowable. God is not a distant or unreachable deity. Human persons can have accessible knowledge of God through their senses of hearing, sight, and touch—most especially through the Person of Jesus Christ. For Catholic Christians, this reveals the utmost importance of Sacred Scripture and the sacraments.

[F]aith-knowledge does not direct our gaze to a purely inward truth. The truth which faith discloses to us is a truth centered on an encounter with Christ, on the contemplation of his life and on the awareness of his presence... (LF, 30)

Thus we can understand why, together with hearing and seeing, Saint John can speak of faith as touch, as he says in his First Letter: "What we have heard, what we have seen with our eyes and touched with our hands, concerning the word of life" (1 Jn. 1:1). By his taking flesh and coming among us, Jesus has touched us, and through the sacraments he continues to touch us even today... (LF, 31)

In venturing deeper on the subject of faith and reason, Francis notes that faith brings light to all the reasonable questions of our time, be they subjective or objective. Truth is solid, apolitical, and more sublime than partisan ideas: we do not possess truth—it possesses us! Truth creates unity, not division.

Truth nowadays is often reduced to the subjective authenticity of the individual, valid only for the life of the individual. A common truth intimidates us, for we identify it with... totalitarian systems. But if truth is a truth of love, if it is a truth disclosed in personal encounter with the Other and with others, then it can be set free from its enclosure in individuals and become part of the common good. As a truth of love, it is not one that can be imposed by force; it is not a truth that stifles the individual. Since it is born of love, it can penetrate to the heart, to the personal core of each man and woman. Clearly, then, faith... grows in respectful coexistence with others. One who believes may not be presumptuous; on the contrary, truth leads to humility, since believers know that, rather than ourselves possessing truth, it is truth which embraces and possesses us. Far from making us inflexible, the security of faith sets us on a journey; it enables witness and dialogue with all. (LF, 34)

Lumen Fidei circumvents arguments that pit religion against science, suggesting that faith lights up a third way. Religion and science need not denounce the other. Indeed, far from being anti-science, faith's inherent openness to truth is a boon to scientific inquiry.

[The light of faith] also illumines the material world, trusts its inherent order and knows that it calls us to an ever widening path of harmony and understanding. The gaze of science thus benefits from faith: faith encourages the scientist to remain constantly open to reality in all its inexhaustible richness. Faith awakens the critical sense by preventing research from being satisfied with its own formulae and helps it to realize that nature is always greater. By stimulating wonder before the profound mystery of creation, faith broadens the horizons of reason to shed greater light on the world which discloses itself to scientific investigation. (LF, 34)