What Is Revelation?
If God exists, why would he need to tell us anything?
Main teaching: De fide
The big question
Suppose God exists. We can already learn a good deal about him by thinking about the world: that it depends on something it did not make, that it shows order and purpose. So why would God need to tell us anything? And if he has, how would we know?
What the Church teaches
God has made himself known in two ways. He can be known with certainty by the natural light of human reason from the things he has made. Beyond that, he has freely chosen to reveal himself and his plan for us directly, by speaking in human history and above all in his Son, Jesus Christ.
How sure is this? De fide. Both points were defined by the First Vatican Council (Dei Filius, chapter 2 and canons 2.1–2.2; DH 3004, 3026–3027). See also the Catechism, CCC 36 and 50–53.
This public revelation is complete. Everything God reveals for our salvation was given in Christ and handed on by the apostles. No new public revelation is to be expected before Christ returns in glory (Dei Verbum 4; CCC 66).
How sure is this? Certain. It is the constant teaching of the Church; Pope Pius X condemned the claim that revelation was not completed with the apostles (Lamentabili, 1907, proposition 21; DH 3421).
Where it comes from
Scripture. The Letter to the Hebrews opens with the whole pattern in two sentences:
In many and various ways God spoke of old to our fathers by the prophets; but in these last days he has spoken to us by a Son. (Hebrews 1:1–2)
St Paul teaches that God can be known from creation: his “invisible nature, namely, his eternal power and deity, has been clearly perceived in the things that have been made” (Romans 1:20). And St John shows why revelation reaches further than reason: “No one has ever seen God; the only-begotten Son, who is in the bosom of the Father, he has made him known” (John 1:18).
That revelation is complete is the point of St Jude’s phrase, “the faith which was once for all delivered to the saints” (Jude 3).
The saints. St John of the Cross, the sixteenth-century Spanish mystic and Doctor of the Church, put it vividly. In giving us his Son, he wrote, God has said everything to us at once in that one Word, and has nothing more to say (Ascent of Mount Carmel, book 2, chapter 22; quoted in CCC 65). Someone who asked God for a new revelation, he added, would be insulting him by not fixing their eyes on Christ.
How theologians explain it
Revelation means God speaking. The classic manuals define revelation as God making truth known to us by way of testimony: not by showing us the evidence, but by telling us. That is why the right response to revelation is faith, which means believing God on his word (Lesson 1.4).
Natural and supernatural revelation. Theologians distinguish two kinds of knowing God:
| Natural knowledge | Supernatural revelation | |
|---|---|---|
| How it comes | Reasoning from created things | God speaking, through prophets and in Christ |
| What it can reach | That God exists; some of his attributes | Everything God chooses to tell us, including mysteries |
| Example | God is the first cause of all things | God is three Persons; God became man |
Why we need revelation. St Thomas Aquinas gives two reasons, and Vatican I adopted both (Summa I, q. 1, a. 1; Dei Filius ch. 2, DH 3005):
- For truths reason could reach in principle. Without revelation, only a few people would arrive at the truth about God, after a long time, and with a mixture of errors. Revelation lets everyone know these truths easily, firmly, and without error.
- For truths beyond reason altogether. God has called us to share his own life, which no creature could ever deserve or discover. We could not aim at that goal unless God told us about it. Truths such as the Trinity and the Incarnation are called mysteries in the strict sense: we could never have found them out, and even once revealed we cannot fully comprehend them.
Public and private revelation. Public revelation is what God gave for the whole human race, completed in Christ and the apostles. Private revelations, such as the apparitions at Lourdes or Fatima, come later. Some are recognised by the Church as worthy of belief, but they belong to a different category. They add nothing to the faith; at most they help people live it more fully at a particular time (CCC 67).
Philosophy bridge
Natural Theology, in the philosophy course, shows how far reason can reach on its own: that God exists, that he is one, and something of what he must be like. Revelation does not cancel that work. It begins where that road ends, and it confirms what reason found.
What the Church does not claim
- Not that reason is useless. The Church defends reason. Vatican I defined that God can be known by reason, against thinkers who said only faith could reach him.
- Not that revelation is a list of facts. God reveals not only truths but himself. The purpose of revelation is to invite us into friendship with him (Dei Verbum 2; CCC 51).
- Not that private revelations are part of the faith. No Catholic is obliged to believe a private revelation with divine faith, even one the Church has approved.
- Not that understanding stops growing. Revelation is complete, but the Church’s understanding of it keeps deepening (CCC 66). Lesson 1.5 explains how.
Check your understanding
- Name the two ways in which God can be known, according to Vatican I.
Show answer
By the natural light of human reason, from the things God has made; and by supernatural revelation, in which God speaks to us directly, above all in his Son.
- If reason can know that God exists, why did God also need to reveal it?
Show answer
So that everyone, not just a few gifted thinkers, could know it easily, with firm certainty, and without error. Left to reason alone, most people would never arrive at it, or would arrive late and with mistakes.
- What is a mystery, in the strict sense used by theologians? Give an example.
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A truth that we could never discover by reason, and that we cannot fully comprehend even after it has been revealed. Examples: the Trinity; the Incarnation.
- A friend says her aunt has received a new message from heaven that every Catholic must accept. How would you answer?
Show answer
Public revelation was completed in Christ and the apostles, and no Catholic is bound to accept a private revelation as part of the faith. Even a private revelation the Church approves adds nothing new; it can only help people live the faith already revealed.
- Why does Hebrews 1:1–2 describe Christ as God’s final word?
Show answer
Because in Christ God speaks not through a messenger but through his own Son, who is himself God. There is nothing greater God could say than to give himself, so everything after Christ is a deeper understanding of him, not something beyond him.