“Claiming to be wise, they became fools, and exchanged the glory of the immortal God for images resembling mortal man and birds and animals and creeping things.” -Romans 1:22–23
The result of their futile thinking is a tragic irony. The gave up the glory of the immortal God, not just for images (idols) resembling mortal man, but also for lower idols resembling birds, animals, and insects. This is the outcome of rejecting God. What else could a darkened foolish heart, contrive.
In one way it’s reminiscent of what scholars have assumed was Gaucus’s stupidity when he and Diomedes exchanged armor on the battlefield of Troy:
For Diomed’s brass arms, of mean device,
For which nine oxen paid, (a vulgar price,)
He gave his own, of gold divinely wrought,
A hundred beeves the shining purchase bought.
Having lost his head, he traded armor of gold worth 100 beef cows for armor of brass that cost just nine oxen.
But likely Paul had in mind Psalm 106:20 “They exchanged the glory of God for the image of an ox that eats grass,” which references the incident in Exodus 32:1-34 where the children of Israel abandon their covenant with God to make golden calves to worship.
One other possible incident could be the Adamic fall in which Adam and Eve, seeking to be wise, only became foolish by partaking of the fruit (Genesis 3:1-7).
In any case, this seems to be the red thread through human history. Man rejects God in order to be his own god; but having rejected the light, his foolish, darkened heart is self-deceptive and he believes the idols he fashions with his own hands (and its pseudo-divinity in which he imparts to it with his futile mind) are the true gods, the true religion of man.