David Murray on How Sermons Work:
Some people seem to think that pastors ‘receive’ their messages direct from God. They imagine some mysterious process by which the pastor just ‘gets’ a sermon. That is too high a view of preaching. It views preachers more like angels than ordinary mortals. I want to show you that, just like any other work, there is a reasonable and logical method and system to follow.
Others think that a pastor just spends the week relaxing, gets up on a Sunday, and says the first thing that comes into his mind with little or no forethought or planning. That is too low a view of preaching. Anyone with a bit of verbal fluency could do it. Behind the thirty to forty-five minutes you see and hear on a Sunday morning are many hours of mental, spiritual, and practical labour. Like all pastoral labour, it involves head, heart, and hand.