A Stanford University researcher who studies persuasion offers an interesting insight into the nature of certainty and expertise. It has me thinking about the nature of preaching.
It is kind of complex, so hang with me.
In the research, it appears that when an expert expresses uncertainty about an opinion it can be more persuasive than an expert who expresses ironclad certainty.
Conversely, a non-expert who expresses certainty is more persuasive.
Listen to the podcast linked above for a description of the research that led to this conclusion.
The research theorizes that the persuasive power arises from the unexpected contrast between the role (expert/non-expert) and the state of certainty. We expect experts to be certain, so when they are not, it surprises us and causes us to focus more on what they say. The unexpected certainty or uncertainty leads us to chew over what they say more carefully, which leads to greater persuasion.
This finding would tend to support the pattern of contemporary preaching that is based on doubts and questions and encourages the pastor to open up his or her own confusion about the Scripture and about God.
There are, however, some significant caveats.
First, this is only true when the person speaking is perceived as an expert. The pastor who overplays that “just one of us” card might find his or her uncertainty having the opposite effect. It is also important to point out that the expert in the research still had an opinion. The expert was trying to persuade the audience of something. Total lack of opinion, obviously, is not persuasive of anything. The issue is whether the expert shared some level uncertainty or not.
But there is even a bigger caveat.
It appears that uncertainty is only persuasive on matters in which the audience believes there is not an objectively true answer. In cases in which the audience believes there is a true answer – a right or wrong report – uncertainty is not persuasive. For instance, research on court testimony shows that juries find experts who are uncertain less persuasive. This is presumably because the jury believes there is a true answer – either the defendant killed a man or not.
If this is true, it could explain why the certainty of some preachers is persuasive. If the audience believes questions about God are answerable and knowable, then, like the jury, they want experts who do not express doubt.
These research insights suggest some interesting observations about the mix of preaching styles and congregational beliefs about God and what can be known about God’s will.
An overly simplistic schema looks like this:
| Nature of God’s will | Persuasive value of uncertainty |
| Can be known | Reduces persuasion |
| Truth can’t be known | Increases persuasion |
In turns out, perhaps, that the reason why some preachers embrace doubt is because that is what persuades their congregations, who fundamentally believe that God’s will cannot be fully known. This is a hypothesis that might be interesting to test.
I am a part-time local pastor serving 
The doctrine of original sin is surely more humbling to man than the opposite: And I know not what honour we can pay to God, if we think man came out of His hands in the condition wherein he is now.
