Or, when was the last time you gave a sermon on the Trinity?
That is a question Dr. Haykin asked us at the beginning of the last class of "The Life and Thought of Augustine." There were a few pastors in the class, and the answer was what he anticipated: not lately. I have been attending my church for twenty years, and I've never heard a sermon on the Trinity specifically. It comes up in passing, but not as the focus on the sermon. I remember once sitting in a lesson to 5th and 6th grade students where the teacher tried to teach about the Trinity, and the typical (inadequate) analogies were given: the egg, water, the shamrock.
Interestingly, a similar discussion arose when Dr. Fowler brought up the content of worship songs (one of his particular pet peeves). He pointed out to us that a popular song actually supported modalism in its lyrics. I asked him if he thought the person in the pew even really gave much thought to that, or could even recognize what modalism is, or do they care?
I can not help but wonder if what we as the congregants expect from our pastors rules out sermons on things like the Trinity. How many of us go into church expecting to be told something to do? We want guidance, but is it guidance that forces us to work through the Scriptures ourselves? Or do we want some kind of therapy? If we expect a sermon to be a group counselling session, then of course the Trinity will not be an appealing subject. It's not really easy to preach the Trinity to begin with, but to find something practical must be a huge task.
The Trinity is a complex thing. It is a mystery. And its "cash value" can't be found in an exhortation to go out and do something. It's one of those truths that shows us who God is. Perhaps we should stop expecting pastors to tell us what to do and just let them preach the truth. Perhaps we should not flinch when they want to preach doctrine.
When school is finished for the semester, I hope to dig into Fred Sanders' two books, The Deep Things of God, and The Triune God. After having studied De Trinitate this past semester, I think it will be helpful to read these.