1 Corinthians 4:19

But I will come to you shortly, if the Lord will, and will know, not the speech of them which are puffed up, but the power (KJV)

Then: Paul makes a strong promise as to his intention to come. It depends on the Lord's will, but when he comes he will learn the hearts of the Corinthians. He will be able to see the Lord's power and authority within them, not through speech, but through their everyday behaviors, the church's spiritual level, and through the attitudes of those outside the church. Those are the main evidences of the Lord's power. Baker (p. 75) speaks to another aspect of the power - that which is seen during the presentation of the gospel. If the Lord is there, then the words of the speaker are more than words. No matter the quality of the rhetoric, the power comes with the Lord's presence.

Now: That the Lord is present, does not excuse the speaker from spending time in prayer, study of the Word, study of the people's needs, and working to improve speaking capabilities. Paul himself tells Timothy, "Study to show thyself approved" (II Timothy 2:). No one can stand up and speak when he lacks knowledge and experience with a topic - Christianity or anything else. The Lord does not normally empower nothingness, but he will bless his faithful, diligent workers with his power. He can and does provide opportunities for learning, training, experience, guidance and his constant presence. Sloppiness, blythe neglect or on-going ignorance have no place in the Lord's work force.

Extra source: Cornerstone Biblical Commentary 1 Corinthians (William Baker), 2 Corinthians (Ralph Martin & Carl Toney), ed. by Philip Comfort. Carol Stream: Tyndale House Publishers, c2006.