He said that a preacher must first believe what he is preaching for people to follow his sermons. Now I thought he meant how passionate the preacher was in preaching. Wrong again.
What makes people believe that a preacher believes what he is preaching is whether or not the preacher lives what he is preaching. Style, mechanics, content, and length are all important, but none of them approach the importance of living the sermon.
St Francis of Assisi said, "Preach the Gospel at all times and when necessary use words."
In other words he was saying that the living the message trumps speaking the message.
I desire to preach the Word of God. That is my calling, but more than preach it, I want people to see me live it. That is what makes the highest impact.
Oh God, fill my inner being so that I may glorify you in deed so that my words will have power.