2:1 And I, when I came to you, brothers, did not come proclaiming to you the testimony of God with lofty speech or wisdom. 2 For I decided to know nothing among you except Jesus Christ and him crucified. 3 And I was with you in weakness and in fear and much trembling, 4 and my speech and my message were not in plausible words of wisdom, but in demonstration of the Spirit and of power, 5 that your faith might not rest in the wisdom of men but in the power of God.
1 Corinthians 2:1-5 (ESV)