The idea that God has any foolishness seems, of itself, quite foolish. And because of the nature of God, it genuinely is. Why, then, does Paul, by divine inspiration (2 Timothy 3:16-17), write "...the foolishness of God is wiser than men, and the weakness of God is stronger than men." (1 Corinthians 1:25)?
Contextually, Paul begins his letter with a standard greeting, then addresses the issue of sectarianism. The Corinthian church had already begun with their carnal divisions, attaching themselves either to Christ Himself, or to individual Apostles. And so Paul asks "Is Christ divided? Was Paul crucified for you? Or were you baptized in the name of Paul?" (1 Corinthians 1:13).
He effectively tells them "you've missed the point", going on to say "For Christ did not send me to baptize, but to preach the gospel, not with wisdom of words, lest the cross of Christ should be made of no effect." (v17). The Gospel, though by God's standard it is wisdom, is here distinguished from wisdom. This seems quite alien to us. Everyone likes to think of themselves as big brained, smarter than each other. And of course, over the centuries, we have overcomplicated things. We forget that the entrance of God's word gives light, and gives understanding to the simple (Psalm 119:130). We elevate our teachers, forgetting that regular meditation on the word makes us far wiser than they (Psalm 119:97-100). We even make the mistake of looking up to those in high places, as if their word matters just because they are considered wise. But Paul continues:
"For the message of the cross is foolishness to those who are perishing, but to us who are being saved it is the power of God. For it is written: “I will destroy the wisdom of the wise, And bring to nothing the understanding of the prudent.” Where is the wise? Where is the scribe? Where is the disputer of this age? Has not God made foolish the wisdom of this world? For since, in the wisdom of God, the world through wisdom did not know God, it pleased God through the foolishness of the message preached to save those who believe.
For Jews request a sign, and Greeks seek after wisdom; but we preach Christ crucified, to the Jews a stumbling block and to the Greeks foolishness, but to those who are called, both Jews and Greeks, Christ the power of God and the wisdom of God. Because the foolishness of God is wiser than men, and the weakness of God is stronger than men. For you see your calling, brethren, that not many wise according to the flesh, not many mighty, not many noble, are called. But God has chosen the foolish things of the world to put to shame the wise, and God has chosen the weak things of the world to put to shame the things which are mighty; and the base things of the world and the things which are despised God has chosen, and the things which are not, to bring to nothing the things that are, that no flesh should glory in His presence.
But of Him you are in Christ Jesus, who became for us wisdom from God—and righteousness and sanctification and redemption— that, as it is written, “He who glories, let him glory in the Lord.”" (v18-31).
So what is the foolishness of God? Nothing in Himself. As if He ever made a mistake. As if He ever had to learn something, or just happens to be the greatest expert in a still unexplored field. He knows all, He sees all, He owns all. There is no foolishness in God. But the foolishness of God is us.
Not much has changed in 2,000 years. We still have different camps of people teaching different kinds of weird things. "Science will save us", "empathy will save us", "government will save us", no. The thing that saves us is this single, wholly unimpressive, first century carpenter who ticked off the wrong people and got himself killed.
It's foolishness. Or so it would appear. It certainly appears that way to the "wise" of this world. Most of them, at least. After all, God desires all men to be saved and come to the knowledge of the truth (1 Timothy 2:3-4), and so we shouldn't be surprised when He brings that to fruition in the lives of some wise men. But if God resists the proud, who is less likely to be saved than he who trusts in his own wisdom?
This world was never going to see Christianity as the fantastic thing that it actually is. Thus, we who believe should always be prepared to be outcasts. Weirdos. The walking freak show. And we shouldn't fit in. This world is perishing. We should have perished with it. But God, ever the showman, decided to demonstrate His incredible power by saving us in this way. As the song goes, "oops, there goes another rubber tree plant".
And so we need to be humble, knowing that it is He who saved us. It's not something we achieved ourselves. We didn't even save ourselves by reasoning ourselves into salvation. The very knowledge we have comes from He who revealed it to us. It all comes from God, from top to bottom, beginning to end, cover to cover. The choice, ultimately, is between looking foolish, or being foolish. To me, the preferable choice seems obvious.