The fact that this church exists at all is proof that God chooses foolish things over wise things, so that nobody might boast before him. You are not wise, righteous, holy and redeemed because of your backgrounds, Paul points out to them, but because you are “in Christ Jesus”. You were foolish people who heard a foolish message preached in a foolish way—and God has demonstrated his wisdom in you so powerfully that the smartest people on earth are left scratching their heads and wondering how he did it. So if you’re going to boast about anything, you should boast in the Lord.
In our preaching and witnessing, our message and our very existence show we are foolish, weak and lowly. So if we are going to blow our trumpets about anything, it had better not be ourselves or any human leaders. Rather, “let the one who boasts boast in the Lord” (1:31).
Paul writes about this in his first letter to the Corinthians, skewering human pride. He does this by drawing a series of contrasts—wise/foolish, strong/weak, influential/ lowly—and showing how the gospel puts us on the “wrong” side of all of them.
Christian preaching is fundamentally foolish, at least in the eyes of the world. The world, in Paul’s day, had all sorts of wonderful techniques to make its messages more acceptable: wisdom, eloquence, intelligence, legal reasoning, philosophy.
Our generation has added the power of advertising, popular music, newspapers, movies, websites and television shows which push a particular vision of the true, the good or the beautiful, and by presenting it well make it seem more plausible. Meanwhile the church is stuck with a method that looked foolish in ancient Corinth and looks even more foolish now: preaching. Not with tricks or stunts. Not with high-budget special effects or virtual-reality immersive experiences. Not with wisdom or eloquence, “lest the cross of Christ be emptied of its power”. Just proclaiming what God has done in Christ and trusting that God will use that message to turn people’s lives the right way up.
Hopefully this is obvious, but this is not an argument for long, dull, rambling, monotone, unimaginative sermons. I have sat through a few of those, and they have nothing to do with Paul’s point here. In this very letter, Paul proves himself a master of punchy, witty, direct, well-illustrated, concise, rhetorical, funny and incisive communication (and I spend a good deal of my time trying to communicate like that myself).