Of course many preachers practice some form of unplanned interaction by just paying attention to the challenges of various members within the congregation. This type of interaction is certainly not to be overlooked, and if you aren't paying attention the lives of the people who attend your local church then it's time to start.
This unplanned interaction is what Fred Craddock has in mind when he says, "[T]he listeners participate in the sermon before it is born. The listeners speak to the preacher before he speaks to them; the minister listens before saying anything" (Preaching, 25).
That's good but, in my opinion, it doesn't go far enough. I believe that churches must begin to include planned interaction as part of what passes for a sermon. In other words, a sermon must be seen as incomplete until the preacher stops talking and starts listening to the responses of the people who are present.
By Planned Interaction I mean, primarily, giving other people a chance to voice their questions, objections, and needs for clarification DURING the time allotted for the sermon.
Why isn't this happening already?
I can't say for certain, but I have a couple of hunches:
1) "Sermonizing" reached its present form in the time after the Protestant Reformation (16th century) when most people couldn't read and were largely uninformed about the current events happening outside their towns. Change is uncomfortable so churches have kept the same format in place ever since.
2) To give a more contemporary explanation, preachers are thinking ahead to their podcast during which people can't interact anyway. Preachers of this sort have in their minds all the people across the world who will be helped and inspired by their sermons, all the while leaving the people in their midst disengaged.
3) The church already has an organized time for interaction and discussion through Sunday School classes or small groups/home groups. This is the response I hear most often, so I answer here by simply pointing out a few things:
a) Most of those extra-curricular groups are attended by less than 50% of church members.
b) People in general, and families in particular, are busier than ever and the time available to sit and get "chummy" with people you see once a week is quickly sliding down the list of priorities for most Americans...yes, even Christian Americans.
c) Unless your church utilizes "sermon-based small groups" those who do attend those other formats are treated to ANOTHER lesson that is based on a different topic than the one that covered in the sermon so their questions related to the sermon are still left unanswered.
Whatever the reason, sermons must change to include interaction. Preachers cannot continue expecting competent and informed people, who provide meaningful insights all week long at their places of employment, to show up each week only to be told, "Thanks for coming, so glad you're here. Now sit down and be quiet."
However, I try to be a realist and I approach the element of interaction realistically. I'm well-aware that some people are in churches that have followed the same order of service for the last hundred years. For pastors in those settings, I believe a compromise can be struck on a looser meaning of interaction than the one I proposed above. In the looser meaning, I still insist that you must give people a chance to voice their questions, objections, and needs for clarification, but instead of doing it during the sermon, it should be done IMMEDIATELY after the worship service has concluded.
Either way, whether you interact in the sense of the primary meaning or secondary meaning, the point remains:
If you desire your sermons to be "stickier" you must interact with those who are present by giving them a chance to speak and be heard.
Elements of a STICKY Sermon - Tension
Elements of a STICKY Sermon - Scripture
Sticky Sermons: Evolution of "The Stickiness Factor"