"For an overseer, as God’s steward, must be above reproach. He must not be arrogant or quick-tempered or a drunkard or violent or greedy for gain, but hospitable, a lover of good, self-controlled, upright, holy, and disciplined." - Titus 1:7-8 

Think about this: "Truth through Personality is our description of real preaching. The truth must come really through the person, not merely over his lips, not merely into his understanding and out through his pen. It must come through his character, his affections, his whole intellectual and moral being. It must come genuinely through him. I think that, granting equal intelligence and study, here is the great difference which we feel between two preachers of the Word." 

- Phillips Brooks, Lectures on Preaching