Is Faith Irrational? Isn't It Just Believing Without Evidence?

The Short Answer

The Catholic Church has never taught that faith means believing without evidence. Faith is trust in God who speaks, and trust is reasonable when there are good grounds for it. Catholics hold that there are such grounds, which the Church calls “motives of credibility” (CCC 156). Faith goes beyond what reason can prove, but it never goes against it: “Though faith is above reason, there can never be any real discrepancy between faith and reason” (CCC 159).

The objection is familiar. Richard Dawkins has described faith as belief held in spite of evidence, or even because evidence is lacking. Mark Twain gave a schoolboy the line: “Faith is believing what you know ain’t so.” Some believers half agree, and speak of faith as a leap in the dark. That is not the Catholic view.

What the Church Does and Does Not Claim

The Church does not claim:

That faith is a feeling. Faith is an act of the mind and will, assenting to what God has revealed.
That faith means switching off your mind. St Peter tells Christians: “Always be prepared to make a defense to any one who calls you to account for the hope that is in you” (1 Peter 3:15).
That we believe because we have proved everything ourselves. We believe “because of the authority of God himself who reveals them, who can neither deceive nor be deceived” (CCC 156, quoting the First Vatican Council).
That believers never have difficulties. They often do. But, as St John Henry Newman put it, “Ten thousand difficulties do not make one doubt” (quoted in CCC 157).

The Church does claim that faith and reason come from the same God, so that “God cannot deny himself, nor can truth ever contradict truth” (CCC 159).

Why Catholics Believe It

All of us live by trust

Most of what any of us knows, we know on someone else’s word. You believe the earth orbits the sun, that your great-grandparents existed, that a country you have never visited is really there. You have not checked these for yourself. You trust reliable witnesses, and that trust is perfectly rational.

Faith works the same way, with a higher witness. The question is not whether faith involves trust, since all knowledge does. It is whether the trust is well-founded: whether there are good reasons to think that God exists and has spoken.

The reasons to believe

The Church points to several:

Reason can know God exists. The classic arguments from the existence and order of the world show that belief in God is reasonable (CCC 36). (See Does God Exist?)
The Resurrection is a historical claim. Christianity stands or falls on an event. St Paul said so himself: “If Christ has not been raised, your faith is futile” (1 Corinthians 15:17). The risen Jesus showed Himself “by many proofs” (Acts 1:3). (See Did Jesus Really Rise From the Dead?)
The signs that accompany faith. The Catechism names “the miracles of Christ and the saints, prophecies, the Church’s growth and holiness, and her fruitfulness and stability” as “the most certain signs of divine Revelation, adapted to the intelligence of all” (CCC 156).
The lives of the saints. Across every century and culture, men and women have been transformed by faith in ways that demand an explanation.

None of these forces belief. Faith is still a free act and a gift of grace (CCC 153–155). But it is a reasonable act, not a blind one.

Faith above reason, not against it

Reason can show that God exists. It cannot tell us that God is a Trinity, or that He became man to save us. For truths like these, God must tell us Himself. Faith accepts what He has said. St Augustine summed up how the two work together: “I believe, in order to understand; and I understand, the better to believe” (quoted in CCC 158). St John Paul II opened his encyclical on the subject with an image: “Faith and reason are like two wings on which the human spirit rises to the contemplation of truth” (Fides et Ratio, opening words).

Common Objections

”Faith means believing without evidence. That’s what the word means.”

That is how some critics use the word, but it is not how Christians have used it. The Letter to the Hebrews describes faith as “the assurance of things hoped for, the conviction of things not seen” (Hebrews 11:1). “Not seen” is not the same as “without evidence.” We do not see electrons, or other people’s thoughts, yet we have good grounds for believing in both.

”Jesus praised those who believe without seeing.”

He did: “Blessed are those who have not seen and yet believe” (John 20:29). But He said it to Thomas, who had refused the testimony of the other apostles. Jesus was not praising believing without reasons. He was praising those who would trust reliable witnesses, as every later Christian must.

”Science has replaced faith.”

Science and faith answer different questions. Science asks how the natural world works; faith concerns who made it and why. The Church teaches that methodical research, done honestly, “can never conflict with the faith, because the things of the world and the things of faith derive from the same God” (CCC 159). Many founders of modern science were devout believers. (See Isn’t Science the Only Real Path to Truth?)

”Doesn’t everyone have faith in something?”

In a sense, yes. Every worldview rests on starting points that cannot be proved by experiment: that the world is intelligible, that our minds can be trusted, that human beings have dignity. The question is not whether you trust, but whether what you trust is worthy of it.

In Summary

Faith, in the Catholic sense, is not believing without evidence. It is a reasonable trust in God who has revealed Himself, supported by real motives of credibility, and freely given as a gift of grace. It goes beyond what reason can prove, but never against it, because the God who gives faith also gave us our minds. Faith and reason are not rivals; they are two wings.

This article follows the method St Robert Bellarmine used in his Controversies*: state the question fairly, clear away misunderstandings, make the case, then answer each objection. See How We Answer Objections.*

Sources

Scripture: Revised Standard Version, Second Catholic Edition (Ignatius Press). John 20:29; Acts 1:3; 1 Corinthians 15:17; Hebrews 11:1; 1 Peter 3:15.
Catechism of the Catholic Church, nn. 36, 153–159. vatican.va
First Vatican Council, Dei Filius (1870), ch. 3.
St John Paul II, Fides et Ratio (1998). vatican.va
St John Henry Newman, Apologia pro Vita Sua (1864), quoted in CCC 157.
Richard Dawkins, speech at the Edinburgh International Science Festival, 15 April 1992, reported in The Independent, 20 April 1992.
Mark Twain, Following the Equator (1897), “Pudd’nhead Wilson’s New Calendar.” twain.lib.virginia.edu