I Corinthians 2:3

And I was with you in weakness, and in fear, and in much trembling (KJV)

Then: Stage fright? Really? Could have been true because Paul is telling all. He's being completely vulnerable in front of people who have already criticized him. That took a lot of courage. He had to be sure the gospel was clearly presented. Through this comment, you might guess he went too far the other way in presenting simple, in being artifice free, and in being open. (Baker, p. 47, infers a unimpressive performance - 2 Cor. 10:1-10 and 11:6.) But that's only speculation. Paul did want the Corinthians to learn both the message and the way to teach it, so Thiselton (p. 213) thinks the fear and trembling is only before God and his responsibility to the Father in heaven. The Corinthians could have seen it both ways. In either case, they understood Paul's intent.

Now: Leaders need the same balance Paul sought. Attract people to hear the message, not the messenger, by being open and clear. Although attracting large congregations to hear the word is important, guage long term effectiveness by the quality, not quantity of those who commit their lives to Christ.

Extra Source: The First Epistle to the Corinthians: a commentary on the Greek text by Anthony C. Thiselton (Eerdman, 2000) http://books.google.com/books?id=IHG_DNLpmroC&dq=First+Corinthians+online+commentaries&printsec=frontcover&source=in&hl=en&ei=oCDBSpeoKZ_e8Ab-zKzBAQ&sa=X&oi=book_result&ct=result&resnum=12#v=onepage&q=&f=false
Cornerstone Biblical Commentary 1 Corinthians (William Baker), 2 Corinthians (Ralph Martin & Carl Toney), ed. by Philip Comfort. Carol Stream: Tyndale House Publishers, c2006.