Paul recalls that when he came to Corinth he did not announce the testimony of God with superior speech or wisdom. He decided to know nothing among them except Jesus Christ and him crucified. He was with them in weakness, fear and much trembling, and his preaching did not rest on persuasive speeches but on a demonstration of the Spirit and of power, so that their faith would rest on the power of God and not on human wisdom.
Among the mature, Paul says, they do speak wisdom, but not the wisdom of this age or of its passing rulers. They speak God's wisdom, mysterious and hidden, which God destined before the ages for our glory. None of the rulers of this age understood it, for if they had they would not have crucified the Lord of glory. Paul backs this with a quotation from Scripture: what no eye has seen nor ear heard, God has prepared for those who love him.
God revealed it to us through the Spirit, who searches everything, even the depths of God. Just as only a person's own spirit knows that person's thoughts, only the Spirit of God knows God's. Believers have received that Spirit so that they may understand what God has freely given them, and they speak of it in words taught by the Spirit. The natural person does not accept these things, for they are foolishness to him and are discerned only spiritually. The spiritual person judges all things, and Paul concludes that believers have the mind of Christ.