What does 1 Corinthians 1:23 mean?

Paul is describing why the gospel message he preaches seems so foolish to so many people. "Foolish," or "folly," in this case, comes from the same Greek word used to form terms such as moron. It's not merely that the world sees the gospel as odd, or unusual. They see it as stupid—as idiotic.

In the previous verse, Paul wrote of the two main cultural forces of his era: religious Jews and intellectual Greeks. He said that the Jews demand miraculous signs as verification that God is at work. The Greeks seek human wisdom by means of logic and skillful speech.

The gospel does not satisfy either group. Instead, Paul says that he and the other apostles preach Christ crucified as the central truth of the gospel. The Jewish people stumble over any suggestion that the Messiah would not immediately overthrow Israel's enemies by the miraculous power of God. They certainly did not want to believe the Messiah would be executed by Israel's occupier Rome in the most humiliating way possible. After all, Deuteronomy 21:23 says that a hanged man is cursed by God, the Jewish leaders would argue.

For the Gentiles, the idea of a God who would serve humanity by offering His own beloved Son as a sacrifice for sin was ridiculous. From a pagan perspective, strong gods required service from people in order to be rewarded. Only the weakest of gods would serve mortal humans, especially in death.

Paul is emphasizing why faith in Christ cannot be arrived at by human religion and human wisdom. For those who believe, however, he will show it holds extraordinary power.