The following introduction and quote are from the Wikipedia entry on Dr. Martin Lloyd-Jones. The questions are mine.
Once, while unfolding to his congregation the internal work of the Holy Spirit in the life of a Christian, Lloyd-Jones marveled at his experience in preaching.
I say it again to the glory of God, this pulpit is the most romantic place in the universe as far as I’m concerned, and for this reason, that I never know what’s going to happen when I get here. Never. My anticipations are often falsified on both sides. This is wonderful. The temptation for the preacher, you see, is to think that if he has prepared what he regards as a good sermon, it’s going to be a wonderful service, and it sometimes can be a very bad one. On the other hand, the poor man may have had a very difficult and a trying week. He may have been very ill, a thousand and one things may have happened to him, and he may go into the pulpit with fear and trembling, feeling that he hasn’t done his work; he’s got nothing. And it may be one of the most glorious services he has ever had the privilege of conducting. Why? Because he doesn’t control the power [within of the Holy Spirit]. It varies. And not only in preaching but in daily life and experience. It is the well of water that is within us and we don’t control it. It controls us.
If a pastor always gets “expected” results, is he in danger of doing ministry apart from the power of the Spirit?
If yes, how does he avoid this tragedy?