Atheists sometimes describe faith as “believing something without evidence.” But is this the way religious believers understand faith? I don’t think so, but I do think that there’s a kernel of truth here and that it’s important to distinguish between faith and knowledge.

First it should be noted that there often lurks a polemical and tendentious understanding of “evidence” behind this definition. The kind of evidence being appealed to is usually the sort of measurable, repeatable evidence appropriate to a scientific experiment (and, it has been well-argued that the scientific enterprise itself rests on a certain kind of faith). But much of our life proceeds on “evidence” in a much wider sense, and there’s no a priori reason to allow this kind of methodological imperialism to go unopposed.

But there is a legitimate point poking out of this straw-man definition. We do distinguish between faith and knowledge, say. Kierkegaard described faith as “the contradiction between the infinite passion of inwardness and the objective uncertainty” That’s a bit more paradoxical than I’d want to put it, skating toward Tertullian’s “I believe because it is absurd,” but it nicely illustrates the point that faith and knowledge are, in some respects, mutually exclusive. If we knew, we wouldn’t need faith.

In the Bible, faith has little to do with belief in God’s existence. Mostly it involves trusting God’s promises, believing that God will be faithful and that he will be vindicated and his purposes fulfilled. Abraham is the archetype of faith because he believed God’s promise that he would be the father of a great nation and acted accordingly.

Often, though, faith involves trusting in God even in the face of evidence to the contrary. Confining ourselves just to the Psalms we often see lamenting that God’s will doesn’t seem to be done on earth: the wicked prosper, the poor and orphaned are oppressed, and God’s people are dragged into exile. And Abraham believed in God’s promise, despite his and his wife’s advanced ages.

So, in the biblical sense there is a distinction between faith and “sight.” We don’t see Gods’ purposes unambiguously realized in the world, but we trust that they will be, even if we can’t see how. Hebrews says that faith is “assurance of things hoped for, the conviction of things not seen” and St. Paul says that we walk by faith and not sight. But this doesn’t mean that we have no reason for our faith, rather it means that the world doesn’t yet reflect the presence of God in such a way as these things would be obvious to anyone. That state of affairs is associated with the end.

And I do think that this tension between faith and sight can apply to the question of God’s existence. Some people claim that God’s existence can be proved (or disproved), but, whatever their merits, these arguments have failed to achieve universal assent, even among well-informed disputants. However, I think many people would agree that our experience of the world is religiously ambiguous.

By this I mean that neither God’s existence nor nonexistence is overwhelmingly obvious. There are certain philosophical considerations that can point to the question of God, such as the sheer existence and order of the universe. There are also, to steal a term from Peter Berger, “signals of transcendence.” I would include here moral, aesthetic, and religious experience of various kinds. But, at least in most cases, these aren’t absolutely compelling on pain of irrationality.

In other words, it’s possible to interpret the totality of our experience in a theistic or non-theistic way. And I think that in this ambiguous situation we find ourselves in it’s possible for reasonable people to differ on the best interpretation. Faith, in this aspect, is trust that there is a God, not in the absence of evidence, but in the face of evidence that is partial and ambiguous. Like the Psalmist who continues to trust in God even in the midst of the exile, the modern believer trusts in God in her exile in this world.

Also, faith isn’t just a set of beliefs about the world, but a commitment to a way of life. It does have an essentially “practical” aspect. And, it can, I think, be reasonable to stick to this commitment even during those periods where the beliefs that undergird it seem doubtful (at least I hope so!). In fact, one strain of the Christian tradition has it that following the path of faith will lead to experiences of “sight” which partly confirm the direction that one is traveling in.

I think that the justification of religious belief ends up being quite agent-relative. There is no algorithm for interpreting the totality of our experience, and each of us will have different particular experiences that we weigh differently, and not in some value-neutral way. That doesn’t mean that there can’t be reasonable debate between adherents of different perspectives, but faith remains (in the words of Keith Ward) “a practical commitment beyond what the evidence would compel any reasonable person to believe” (Pascal’s Fire, p. 223).