18 For the wrath of God is revealed from heaven against all ungodliness and unrighteousness of men, who by their unrighteousness suppress the truth.19 For what can be known about God is plain to them, because God has shown it to them. 20 For his invisible attributes, namely, his eternal power and divine nature, have been clearly perceived, ever since the creation of the world, in the things that have been made. So they are without excuse. 21 For although they knew God, they did not honor him as God or give thanks to him, but they became futile in their thinking, and their foolish hearts were darkened.22 Claiming to be wise, they became fools, 23 and exchanged the glory of the immortal God for images resembling mortal man and birds and animals and creeping things.
Did you know that God does not believe in atheists? Here’s how J. Ligon Duncan has put it:
There is no such thing as an atheist, Paul is saying. There’s no such thing as an atheist, an agnostic. No one can claim ignorance. The apostle Paul says everyone knows God because God Himself has made Himself evident to them. All men have a knowledge of God, not just a bear awareness of his existence. They are not blind in this sense. They know God. God is plainly seen. He is evident within them. And so our suppression, the suppression that he talks about in verse 18, is culpable. You can’t suppress something you don’t have. And suppressing that knowledge of the truth makes us liable for sin. Listen to what Donald McCloud says. “It is because we know the truth that man’s godliness is inexcusable.”
Paul’s argument is not that a man’s ignorance is inexcusable because God’s revelation is so clear, but that man’s religious behavior, or lack of it, is inexcusable because man is not ignorant. Paul is saying we know, and we still don’t worship; we still don’t obey, we still don’t love God; we still don’t love our neighbor. We know it, and we don’t do it. We rebel against it. Sin is whole-soul rebellion against God. There’s no such thing as an atheist. Often people say well what about the native in Africa. That’s not a very politically correct thing to ask anymore, but you know what they’re getting at. And Paul’s answer is quick. It’s at the tip of his tongue. And he says there’s nobody who doesn’t know. We don’t have to go out and tell them the gospel so that they know the one true God. Paul says they already know the one true God, and they choose not to worship Him, or reverence Him, or adore Him, or obey him, or believe Him. They all know, and they suppress the truth.