Romans 1:20 says “for the invisible things of him from the creation of the world are clearly seen, being understood by the things that are made, even his eternal power and Godhead, so without excuse.” Every human being has the knowledge of God. There’s no such thing as an atheist. I’ve seen professing atheists backslide within 30 seconds. You can make them backslide. If you meet someone who says “I’m an atheist”, just say “So you believe that nothing created everything, a scientific impossibility? and watch their facial expression. “No, not nothing created everything” so say “You believe there was something that created everything it, just wasn’t God?” “Yeah, that’s it.” “Obviously you’re not an atheist, you’re agnostic. You believe something created everything, it just wasn’t God. Let’s see if we can find out why you don’t want it to be God.” You take him through the commandments and find that they’re lying, thieving, fornicating, blasphemous, adulterers at heart and the problem isn’t intellectual; it’s moral. They can’t find God for the same reason a thief can’t find a policeman. They’re not interested.