" The wrath of God is being revealed from heaven against all the godlessness and wickedness of people, who suppress the truth by their wickedness, 19 since what may be known about God is plain to them, because God has made it plain to them. 20 For since the creation of the world God’s invisible qualities—his eternal power and divine nature—have been clearly seen, being understood from what has been made, so that people are without excuse.
21 For although they knew God, they neither glorified him as God nor gave thanks to him, but their thinking became futile and their foolish hearts were darkened."
So here is how a conversion with my soon to be 8 year old went this afternoon, which started out of nowhere (which is typical of him):
Joho: "How do we know that God exists?"
Me: "The Bible tells us so."
Joho: "How do we know the Bible was not made up?"
Me: "Because it has endured the test of time and because a lot of its claims are historical facts, such as the death and resurrection of Jesus Christ (acknowledged by believers and unbelievers alike)."
Me: "Why do you ask?"
Joho: "Just wondering."
Jojo: "because it feels so real."
Me: "What do you mean? What feels so real? That God exists?"
Then I went on telling him how God has put the sense of Himself in us, and those who do not believe, do so because, as the Bible says, they have suppressed the knowledge of God and persistently do so.
I was also reminded of J. I Packer's reflection on that passage in Romans:
"How is this disclosure made? It imprints itself directly on every person's conscience: . . . No one is entirely without inkling of judgment to come. And this immediate disclosure is confirmed by the revealed word of the gospel, which prepares us for its good news by telling us the bad news of a coming "day of wrath and revelation of the righteous judgment of God"."