A preacher can proclaim anything in a stained-glass voice, at 11.30 on a Sunday morning, following the singing of hymns. Yet when a preacher fails to preach the Scriptures, he abandons his authority. He confronts his hearers no longer with a word from God but only with another word from men. Therefore most modern preaching evokes nothing more than a wide yawn. God is not in it.
Haddon Robinson (Expository Preaching)