The ‘tenor of scripture’ implies everyone knows God. Humans do not need to analyze the world to find God. Here is an excerpt of a sermon by Douglas Douma who expounds this idea: https://douglasdouma.wordpress.com/2017/09/05/sermon-on-romans-118-32/
I. All men know God. (vs. 19-22)
Paul begins this passage with some very interesting statements about man’s knowledge of God.
His claim is that there are no atheists! Though there are some people who profess to be atheists, Paul tells us that in truth all men know God. But in their sin, men suppress their knowledge of God.
But HOW do all men know God? We haven’t seen him, so how can we be sure that he exists?
Paul says, “what can be known about God is plain to them, because God has shown it to them. For his invisible attributes, namely, his eternal power and divine nature, have been clearly perceived, ever since the creation of the world.”
Some theologians have held that Paul is essentially stating a form of what has been known as “The Design Argument for the Existence of God.”
The Design Argument is essentially that since the universe appears to have design to it, it must have a Designer; there must be a God.
Thomas Aquinas, the great Catholic theologian, held this view. He basically borrowed it from the Pagan Aristotle. Some Protestants have also held this view. The most famous representative is William Paley and his “Watchmaker Argument.” Paley contended that just as when you find a complex watch on the ground and make the inference that it was made by a designer, so when you see the complex universe around you, you can correctly infer that a God designed it.
So this is one view of what Paul is saying in Romans 1:20 when he writes, “God’s invisible attributes have been clearly perceived, ever since the beginning of the world.”
There has been a long history of debate, however, on the validity of such “Design arguments.” And there may even be good reason to think there are flaws in the argument.
Fortunately, there is, I think, a better view of what Paul is saying. Rather than understanding Paul to be saying “When you look at nature you come to know God” I think he is best understood as saying “YOU ALREADY KNOW GOD, and so when you look at nature, you can understand that He is the cause of it all.”
This may be a surprising thing to hear. Rather than making arguments for the existence of God, many Reformed theologians argue that the Bible teaches that we are BORN with a knowledge of God. It is INNATE in our minds. Similarly, the law of God is “written on our hearts.”
It is because we retain an element of God’s Image in us that we know God already. We know him innately, or as John Calvin says we have the “sense of the divine,” the “sensus divinitatus” and thus when we look at nature, already knowing God in our minds, we attribute the great things we see to His power.
b. Therefore, all men are without excuse. (vs. 20b)
Therefore, as we continue in Paul’s argument, since all men are born with a knowledge of God, and understand his power to be evident in the world, all men are without excuse when they do not worship or obey Him.
God is even known to those who are born blind, because knowledge of God is within all men from birth. Therefore, there is no excuse.
You may have had someone question you, “What about the man who lives on a far away island, and has never heard of the Bible, shouldn’t he be given a pass by God if he does not believe?”
How do you think Paul would answer?
He would say “By no means!” [one of his favorite phrases] Because all men — even those on far away islands — are born with a knowledge of God, they are without excuse.
As will become a stronger and stronger theme as we continue in the book of Romans, no one is righteous. All people need the grace of God for salvation. They need his righteousness as a gift to them.
II. All men are unrighteousness.
So, knowing there is a God, but then ignoring Him and acting according to one’s own desires, the unrighteousness of man is clearly seen.