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. – 1 Corinthians 1:21 (NKJV)

“In some ways, the entire process seems ridiculous.  Common sense rebels against claims that eternal destinies will change simply because we voice thoughts from an ancient text.  When Paul commends the foolishness of preaching – not foolish preaching – he acknowledges the apparent senselessness of trying to transform attitudes, lifestyles, philosophical perspectives and faith commitments with mere words about a once crucified rabbi (see 1 Cor. 1:21). Yet preaching endures and the gospel spreads because the Holy Spirit uses puny human efforts as the conduit for the force of his own Word.  By the blessing of God’s Spirit, the Word yet transforms (i.e., causes our hearts to love God and our wills to seek his will).”  

– Bryan Chapell, in Christ-Centered Preaching: Redeeming the Expository Sermon, pp. 28-29