‘There is no need for me to prepare before preaching’, somebody argues; ‘I shall rely on the Holy Spirit to give me the words. Jesus himself promised that it would be given us in that hour what we are to say.’ Such talk sounds plausible, until we remember that the misquotation of Scripture is the devil’s game. Jesus was referring to the hour of persecution not of proclamation, and to the prisoner’s dock in a law court, not the pulpit in a church. Trust in the Holy Spirit is not intended to save us the bother of preparation. The Holy Spirit can indeed give us utterance if we are suddenly called upon to speak and there has been no opportunity to prepare. But he can also clarify and direct our thinking in our study. Indeed, experience suggests that he does a better job there than in the pulpit.
– John Stott