What does 1 Corinthians 1:21 mean?

Paul is declaring a powerful truth: The reason so many fail to believe in Christ's death on the cross as the way to be forgiven from their own sin is not because the idea is too hard to understand. It's because it is too easy. It is foolishness for simpletons, as an unbeliever sees it.

Humanity at large has failed to come to know God through human wisdom. The language Paul uses suggests that God, in His wisdom, did not allow human wisdom to bring them to Him. Instead, it pleased Him to save those who believe through the folly of what Paul and the other apostles preach.

In other words, Paul understands that his message, the gospel, looks and sounds foolish to most of the world. People trusting their own wisdom or the wisdom of others will miss it. The gospel is not something that can be worked out by logic and philosophy. Evidence can lead us towards the truth (Romans 1:18–20; Psalm 19:1; Matthew 7:7–8), but that truth ultimately has to be accepted as revelation from God.

Does this mean Paul discourages the use of the mind or logical arguments? Based on his writings in Scripture, he clearly does not. He was an intelligent, well-educated man who routinely used powerful arguments in his ministry (Philippians 3:4–8; Acts 17:17). His point is that human wisdom, knowledge, and logic cannot bring someone to faith in the Christ who died for their sin on the cross.