In Romans, Paul explains that people “knew God,” yet “they did not honor him as God or give thanks to him” (Rom 1:21). What does it mean for people to know God by nature without honouring or thanking him? And how can they know God when apart from the Gospel, no one can be saved?
Here is my answer: Anyone can know the signs of deity but only grace brings us to the reality to which the signs point. Hence, Paul claims that anyone can discern God’s invisible attributes but they neither give thanks to him nor honour him.
People can naturally know by negation
People can know God by his attributes but only by way of negation (his unseen attributes). And this only makes sense when we remember how God created the world and how the world reflects his glory.
God created the world by a voiced Word (“Let there be light”) and the world answers back voicelessly (“The heavens declare the glory of God”).
For centuries, Christians have tried to put this to words with varying levels of success (see Maximos or the Damascene or Thomas).
But a basic answer is that nature provides us with all the signs of deity. Even philosophers like Plato rightly discerned the signs of deity in creation. But he fell silent at the reality behind them. He turned to apophatic (negative) reasoning to know God. For him, the divine must be invisible (not visible) immutable (not changing), and uncircumscribed (not limited by space).
In the early 100s, Justin Martyr sought God through philosophy. After many disappointments, he met a mysterious Christian elder who spoke to him a better word than the philosophy of Athans. The elder who spoke a better word to Justin Martyr (c. 130) showed him the reality. God had to reveal himself so that we could have a spiritual vision of God.
Paul concurs. He asks, “And how are they to believe in him of whom they have never heard?” (Rom 10:14). The answer is obvious: they cannot believe in him. They know him by way of negation (his invisible attributes). Only by revelation and especially the revelation of God in Christ can they begin to know God by faith and begin to see him really.
People can supernaturally know by faith
Apart from the Gospel, no one can savingly know God. No one can gain eternal life. Yet by Christ’s assumption of humanity, God provided us with a full revelation of God. In Christ, we see God. We have the first insight into God through our union with Christ.
God speaks a new creation in hearts, “let there be light.” The Spirit quickens us to see Christ’s face in which we see the glory of the Father (2 Cor 3:18–4:6). We move from darkness into light. “In your light,” the psalmist writes, “do we see light” (Ps 36:9). God in Christ is the fountain of life (Ps 36:9)—an overflowing well of water that bubbles over into eternal life (John 4:13–14).
In Christ, we have the life of God, eternal life (see John 17:3). But this great gift that we have can only come when God reveals himself to us. He elected Israel and become their God (Deut 8). He must initiate the relationship with us now too. And he has by sending his Son into the world who enlightens everyone (John 1:9).
By faith, we receive Christ. We receive life. And this is something nature cannot provide.
Only special revelation can bring us to God. Nature alone cannot.