Concise Theology by J.I. Packer
The heavens declare the glory of God; the skies proclaim the work of his hands. PSALM 19:1
God’s world is not a shield hiding the Creator’s power and majesty. From the natural order it is evident that a mighty and majestic Creator is there. Paul says this in Romans 1:19-21, and in Acts 17:28 he calls a Greek poet as witness that humans are divinely created. Paul also affirms that the goodness of this Creator becomes evident from kindly providences (Acts 14:17; cf. Rom. 2:4), and that some at least of the demands of his holy law are known to every human conscience (Rom. 2:14-15), along with the uncomfortable certainty of eventual retributive judgment (Rom. 1:32). These evident certainties constitute the content of general revelation.
General revelation is so called because everyone receives it, just by virtue of being alive in God’s world. This has been so from the start of human history. God actively discloses these aspects of himself to all human beings, so that in every case failure to thank and serve the Creator in righteousness is sin against knowledge, and denials of having received this knowledge should not be taken seriously. God’s universal revelation of his power, praiseworthiness, and moral claim is the basis of Paul’s indictment of the whole human race as sinful and guilty before God for failing to serve him as we should (Rom. 1:18-3:19).
God has now supplemented general revelation with the further revelation of himself as Savior of sinners through Jesus Christ. This revelation, given in history and embodied in Scripture, and opening the door of salvation to the lost, is usually called special or specific revelation. It includes explicit verbal statement of all that general revelation tells us about God, and teaches us to recognize that revelation in the natural order, in the events of history, and in the makeup of human beings, so that we learn to see the entire world as, in Calvin’s phrase, a theatre of the glory of God.