Helpful diagnostic questions from Kent Hughes:
(you can watch this, or read the transcript below)
Was I True to the Word?
We should begin with a warning, a caveat. You actually can’t tell how effective a sermon was by the response you receive. People could say to you, “That was a wonderful sermon,” and really nothing effectual happens out of it. Or you could be thinking, “I got no response,” and then five years later someone will come and say, “I was in church on that day and the Lord spoke to me.” I’ve had people tell me they were regenerated and I couldn’t remember the sermon.
So you need to be careful about this kind of subjective evaluation, because it is generally assessed by how the people responded.
With that said, I think there are other canons for measuring a sermon. Was I true to the Word? Was I clear? Was I preaching myself? In other words, Was I too much in the foreground or was I preaching the Word? Scripture says we don’t preach ourselves. Was I dependent upon the Holy Spirit? Was my heart pure? Was I offering it to God? Those are the kind of canons by which you should measure a sermon.
There are other questions as well. There’s the issue of work ethic. Did I really do the job? I have rarely stepped in the pulpit unprepared. But if I was unprepared, I wasn’t very confident it would go too well. That is, unless my lack of preparation was, for example, because someone died on Saturday and I had spent all day with the family. In those situations, the Lord provides.
In the end, the Lord smiles on the labors of his pastors.