Definition of Revelation. Revelation is the discovery of truth.
Definition of Natural Revelation. Natural revelation is the discovery of truth by one's natural powers.
Example of Natural Revelation. Euclid's discovery of a proof of the infinitude of the prime numbers is an example of natural revelation.
The Catholic Church holds that one can know many theological truths by natural revelation, including the following true propositions:
- God exists;
- God rewards good and punishes evil;
- The soul survives bodily death and enters into eternal happiness or eternal misery;
- There is an objective moral law.
The Church teaches that all rational minds have known these truths. The Church also explains that an otherwise rational person may deny these truths due to the depravity of their heart. Indeed, the Psalmist assures us that unbelief roots in the heart, not the mind; it is axiological, not doxastic.
Psalm 13:1. The fool hath said in his heart: There is no God.
Other theological truths are open to natural revelation, not just those bulleted above. Natural Theology, a branch of Metaphysics, studies those theological truths open to natural revelation.
Definition of Supernatural Revelation. Supernatural revelation is the manifestation of truth by God to us. There is nothing in our nature that could discover such truths without the help of God; hence such revelation is properly called supernatural.
How does God communicate such truths to us? God declares the truths of supernatural revelation through Prophets, Apostles, Scripture, and -- above all else -- Jesus Christ.