A preacher must always convey the impression that he himself has been gripped by what he is saying. If he has not been gripped nobody else will be. So this is absolutely essential. He must impress the people by the fact that he is taken up and absorbed by what he is doing. He is full of matter, and he is anxious to impart this. He is so moved and thrilled by it himself that he wants everybody else to share in this. He is concerned about them; that is why he is preaching to them. He is anxious about them; anxious to help them, anxious to tell them the truth of God. So he does it with energy, with zeal, and with this obvious concern for people.
Martyn Lloyd-Jones