John Calvin on the world as Mirror

Calvin starts a sermon on Genesis 1:1-2 with these words,

Even though men maliciously try to obscure God's glory, it is certain that they cannot open their eyes and look in any direction without seeing evidence that leads to knowledge of him, knowledge will they flee and would like to bury completely if they could. God shows himself everywhere and provides indications of his majesty, of his power, of his righteousness, of his goodness, and everything which can lead to him. That is also why Paul in the fourteenth chapter of Acts says that God cannot leave himself without witness (Acts 14:17), for all things created do not have their source in themselves. It is as if God were enlightening us to draw us to himself and make us aware that he is the fountain and origin of all things, that everything depends on him, and that everything is founded on and sustained by his power. Hence, the world, from its heights to its depths, is like a mirror to compel us to contemplate God, who is by nature and in essence invisible. Paul says the same thing in the first chapter of Romans, that the things we perceive with our eyes show us that there is one God (Rom. 1:20), although he is in himself incomprehensible unless we understand him in his works. At least we are responsible, and we will be inexcusable if we remain locked in our ignorance. 

John Calvin's Sermons on Genesis: Chapters 1-11. Trans. Rob Roy McGregor. East Peoria, IL: The Banner of Truth Trust. 2009. pp. 1-2.