Romans 1:18-25 ESV
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. 24 Therefore God gave them up in the lusts of their hearts to impurity, to the dishonoring of their bodies among themselves, 25 because they exchanged the truth about God for a lie and worshiped and served the creature rather than the Creator, who is blessed forever! Amen.
Psalm 139:7-10 ESV
7 Where shall I go from your Spirit? Or where shall I flee from your presence? 8 If I ascend to heaven, you are there! If I make my bed in Sheol, you are there! 9 If I take the wings of the morning and dwell in the uttermost parts of the sea, 10 even there your hand shall lead me, and your right hand shall hold me.
Paul argues that the universe clearly points to an Almighty Creator, in a way that is clearly perceived by everyone. The psalmist complements this by adding that the presence of God can be perceived anywhere, no matter where one goes. Combining both descriptions, the picture one gets is that the existence and presence of God ought to be undeniably obvious.
However, these conclusions are challenged by an increasingly popular argument known as the Argument from Divine Hiddenness. The following are handy sources to learn about this argument:
- https://iep.utm.edu/divine-hiddenness-argument-against-gods-existence/
- https://plato.stanford.edu/entries/divine-hiddenness/
The argument in question was in fact brought up in a recent answer to Is Romans 1:19-20 philosophically sound? on Philosophy Stack Exchange:
Aside from a lack of philosophical argument in the verse you posted (which I’m sure someone else will answer), there is actually a philosophical debate about how God is hidden, rather than being “clearly perceived”: if God exists, why is he hidden from us?
Here is a summary from the IEP article for it:
these arguments try to demonstrate that, if God existed, He would (or would likely) make the truth of His existence more obvious to everyone than it is. Since the truth of God’s existence is not as obvious to everyone as it should be if God existed, proponents of arguments from divine hiddenness conclude that God must not (or probably does not) exist.
As the article explains, the problem rests on the assumption that God has hidden his existence from us, or at the very least been reluctant to give evidence that point towards his existence. If there were clear signs towards his existence, nonbelief would be less prevalent than it currently is.
There are some good arguments against the Atheist position (which you can find in the article), but since there is an ongoing debate about the hiddenness of God I would say the argument in the verses you posted doesn’t hold up philosophically.
If the existence and presence of God are unmistakably and undeniably evident, how do we explain the traction and impact that the argument from divine hiddenness seems to be gaining among atheists?
Note: Attempts to trivialize the question by answering "because they are atheists" are out of scope, because such answers would fail to explain why the individuals in question are atheists in the first place (which should be surprising given the fact that, according to Romans 1:19-20 and Psalm 139:7-10 and similar passages, theism should be undeniably evident to everyone).